Surface treatment apparatus

ABSTRACT

Inside a single apparatus main body ( 100 ), a surface treatment apparatus includes: a treatment cell ( 11 ); a vertical rotation shaft ( 12 ); an attachment/detachment device; a receiving tank ( 15 ); a cover body ( 16 ); a plurality of tanks ( 21 ); a plurality of surface treatment liquid supply devices ( 22 ); a cleaning water supply device; a drain device ( 3 ); and a first cleaning device. Upon operation of the surface treatment liquid supply device while the treatment cell ( 11 ) containing small objects is rotated by the vertical rotation shaft ( 12 ), a surface treatment is carried out on the small objects, upon operation of the cleaning water supply device, the small objects inside the treatment cell ( 11 ) are cleaned, and upon operation of the first cleaning device, the inner face of the cover body and the outer face of the treatment cell are cleaned, thus providing circulation use of surface treatment liquids in the tanks.

TECHNICAL FIELD

The present invention relates to surface treatment apparatuses forsurface-treating small objects. Examples of small objects include smallcomponents such as a powdery work, a chip capacitor, a diode, aconnector, a reed switch, a nail, a bolt, a nut, and a washer, eachhaving a size of 0.5 to 5000 μm.

BACKGROUND ART

As surface treatment apparatuses for surface-treating small objects,apparatuses disclosed in Patent Documents 1 and 2, for example, areknown. In each of these apparatuses, while a treatment cell containingsmall objects is rotated, a surface treatment liquid is injected intothe treatment cell, thereby surface-treating the small objects.

-   [Patent Document 1] Japanese Unexamined Patent Application    Publication No. 11-505295-   [Patent Document 2] U.S. Pat. No. 5,879,520

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention

Actually, in the above-mentioned conventional apparatuses, surfacetreatment liquids are scattered and/or leaked, thereby causing a problemthat the inside and/or outside of each of the apparatuses are/is soiled.

Further, when small objects are surface-treated, normally, a firstsurface treatment is carried out, and a second surface treatment is thencarried out by using a desired metal. In other words, two types ofsurface treatments are carried out. Furthermore, normally, surfacetreatment liquids, which have been used for two types of surfacetreatments, are each collected and reused. Accordingly, when two typesof surface treatments are performed in a single surface treatmentapparatus, respective surface treatment liquids are desired to bestrictly separately collected so as not to be mixed with each other.Whereas, in the conventional single surface treatment apparatus, suchcollection has not necessarily been sufficiently performed.

An object of the present invention is to provide a surface treatmentapparatus capable of preventing the inside and/or outside of theapparatus from being soiled, and another object of the present inventionis to provide a surface treatment apparatus capable of achieving, as amain effect, strict separate collection and reuse of two types ofsurface treatment liquids in the single apparatus.

Solution to the Problems

A surface treatment apparatus according to a first aspect of the presentinvention serves as a surface treatment apparatus for carrying out asurface treatment on small objects while rotating a treatment cellcontaining the small objects, the surface treatment apparatus including:a treatment cell having liquid flow-out means for allowing a liquid toflow out from inside to outside, and capable of containing the smallobjects; a receiving tank surrounding the treatment cell from below; acover body provided so as to cover the receiving tank from above, thecover body having an opening at its center; surface treatment liquidsupply means for supplying a surface treatment liquid to the inside ofthe treatment cell; and cleaning water supply means for supplyingcleaning water to the inside of the treatment cell, wherein when thesurface treatment liquid supply means is operated while the treatmentcell is rotated, the surface treatment liquid is supplied to the insideof the treatment cell, and the surface treatment liquid is allowed toflow out from the treatment cell through the liquid flow-out means,thereby carrying out a surface treatment on the small objects, whereinwhen the cleaning water supply means is operated while the treatmentcell is rotated, the cleaning water is supplied to the inside of thetreatment cell, and the cleaning water is allowed to flow out from thetreatment cell through the liquid flow-out means, thereby cleaning thesmall objects, wherein the apparatus further includes first cleaningmeans for ejecting the cleaning water onto an inner face of the coverbody and/or an outer face of the treatment cell, and wherein when thefirst cleaning means is operated while the treatment cell is rotated,the inner face of the cover body and/or the outer face of the treatmentcell are/is cleaned.

A surface treatment apparatus according to a second aspect of thepresent invention serves as a surface treatment apparatus for carryingout a surface treatment on small objects while rotating a treatment cellcontaining the small objects, the surface treatment apparatus including:a treatment cell having liquid flow-out means for allowing a liquid toflow out from inside to outside, and capable of containing the smallobjects; a receiving tank surrounding the treatment cell from below; acover body provided so as to cover the receiving tank from above, thecover body having an opening at its center; surface treatment liquidsupply means for supplying a surface treatment liquid to the inside ofthe treatment cell; and cleaning water supply means for supplyingcleaning water to the inside of the treatment cell, wherein when thesurface treatment liquid supply means is operated while the treatmentcell is rotated, the surface treatment liquid is supplied to the insideof the treatment cell, and the surface treatment liquid is allowed toflow out from the treatment cell through the liquid flow-out means,thereby carrying out a surface treatment on the small objects, whereinwhen the cleaning water supply means is operated while the treatmentcell is rotated, the cleaning water is supplied to the inside of thetreatment cell, and the cleaning water is allowed to flow out from thetreatment cell through the liquid flow-out means, thereby cleaning thesmall objects, wherein the apparatus further includes opening/closingmeans for opening/closing the cover body relative to the receiving tank,and wherein the opening/closing means raises/lowers the cover body to apredetermined height from a position at which the cover body covers thereceiving tank, with the cover body kept in a horizontal state, andfurther moves the cover body from the predetermined height so that thecover body gets away from the receiving tank.

A surface treatment apparatus according to a third aspect of the presentinvention serves as a surface treatment apparatus for carrying out asurface treatment on small objects while rotating a treatment cellcontaining the small objects, the surface treatment apparatus including:a treatment cell having liquid flow-out means for allowing a liquid toflow out from inside to outside, and capable of containing the smallobjects; a receiving tank surrounding the treatment cell from below; acover body provided so as to cover the receiving tank from above, thecover body having an opening at its center; a tank for containing asurface treatment liquid; surface treatment liquid supply means forsupplying the surface treatment liquid, contained in the tank, to theinside of the treatment cell; cleaning water supply means for supplyingcleaning water to the inside of the treatment cell; and drain means forreturning the surface treatment liquid, received by the receiving tank,to the tank containing the surface treatment liquid, and for flowing thecleaning water, received by the receiving tank, to a discharge portion,wherein when the surface treatment liquid supply means is operated whilethe treatment cell is rotated, the surface treatment liquid is suppliedto the inside of the treatment cell, and the surface treatment liquid isallowed to flow out from the treatment cell through the liquid flow-outmeans, thereby carrying out a surface treatment on the small objects,wherein when the cleaning water supply means is operated while thetreatment cell is rotated, the cleaning water is supplied to the insideof the treatment cell, and the cleaning water is allowed to flow outfrom the treatment cell through the liquid flow-out means, therebycleaning the small objects, wherein the drain means includes: adischarge member communicated with a discharge port of the receivingtank; a connecting pipe provided so as to be connected to an end portionof the discharge member or to each of inlets of the tank and thedischarge portion in a manner movable up and down; a raising andlowering portion for moving up and down the connecting pipe; and movingmeans for moving the end portion of the discharge member, and whereinthe end portion of the discharge member is moved so as to be locatedabove a selected one of the inlets of the tank and the dischargeportion, and the connecting pipe is raised or lowered, therebyconnecting the discharge member with the inlet via the connecting pipe.

A surface treatment apparatus according to a fourth aspect of thepresent invention serves as a surface treatment apparatus for carryingout two types of surface treatments on small objects while rotating atreatment cell containing the small objects, the surface treatmentapparatus including: a treatment cell having liquid flow-out means forallowing a liquid to flow out from inside to outside, and capable ofcontaining the small objects; a receiving tank surrounding the treatmentcell from below; a cover body provided so as to cover the receiving tankfrom above, the cover body having an opening at its center; two tanksfor individually containing two types of surface treatment liquids; twosurface treatment liquid supply means for individually supplying thesurface treatment liquids, contained in the two tanks, to the inside ofthe treatment cell; cleaning water supply means for supplying cleaningwater to the inside of the treatment cell; and drain means for returningthe surface treatment liquid, received by the receiving tank, to thetank containing the surface treatment liquid, and for flowing thecleaning water, received by the receiving tank, to a discharge portion,wherein when the surface treatment liquid supply means is operated whilethe treatment cell is rotated, the surface treatment liquid is suppliedto the inside of the treatment cell, and the surface treatment liquid isallowed to flow out from the treatment cell through the liquid flow-outmeans, thereby carrying out a surface treatment on the small objects,wherein when the cleaning water supply means is operated while thetreatment cell is rotated, the cleaning water is supplied to the insideof the treatment cell, and the cleaning water is allowed to flow outfrom the treatment cell through the liquid flow-out means, therebycleaning the small objects, wherein the apparatus further includes firstcleaning means for ejecting the cleaning water onto an inner face of thecover body and/or an outer face of the treatment cell, wherein when thefirst cleaning means is operated while the treatment cell is rotated,the inner face of the cover body and/or the outer face of the treatmentcell are/is cleaned, wherein the apparatus further includesopening/closing means for opening/closing the cover body relative to thereceiving tank, wherein the opening/closing means raises/lowers thecover body to a predetermined height from a position at which the coverbody covers the receiving tank, with the cover body kept in a horizontalstate, and further moves the cover body from the predetermined height sothat the cover body gets away from the receiving tank, wherein the drainmeans includes: a discharge member communicated with a discharge port ofthe receiving tank; a connecting pipe provided so as to be connected toan end portion of the discharge member or to each of inlets of the twotanks and the discharge portion in a manner movable up and down; araising and lowering portion for moving up and down the connecting pipe;and moving means for moving the end portion of the discharge member, andwherein the end portion of the discharge member is moved so as to belocated above a selected one of the inlets of the two tanks and thedischarge portion, and the connecting pipe is raised or lowered, therebyconnecting the discharge member with the inlet via the connecting pipe.

In the present invention, the following specific structures arepreferably further adopted as appropriate.

(a) The first cleaning means includes a first ejection portion and/or asecond ejection portion for ejecting cleaning water, wherein the firstejection portion includes an ejection port formed in a water supplypassage provided along an edge of the opening of the cover body, andejects the cleaning water onto the inner face of the cover body, andwherein the second ejection portion includes an ejection port formed ina water supply passage provided along the inner face of the cover body,and ejects the cleaning water onto the outer face of the treatment cell.

(b) The opening/closing means includes: an arm extending from the coverbody; a rotary body provided at the other end side of the arm, andsupported so as to be rotatable around a horizontal axis orthogonal tothe arm; a horizontal support shaft for rotatably supporting the arm;support means for supporting the arm so as to prevent a portion of thearm adjacent to the cover body from going down with the horizontalsupport shaft serving as a supporting point; raising and lowering meansfor raising and lowering the horizontal support shaft together with thearm; and an abutment body against which the rotary body of the arm,raised to a predetermined height, abuts from below, wherein upon raisingof the horizontal support shaft, the cover body is raised while beingkept in a horizontal state until the rotary body abuts against theabutment body, and after the rotary body has abutted against theabutment body, the cover body is raised while being inclined along withthe rotation of the arm around the horizontal support shaft.

(c) The apparatus includes second cleaning means for ejecting cleaningwater onto an inner face of the discharge member.

In the present invention, the following specific structures may befurther adopted as appropriate.

(I) The apparatus further includes an anode electrode, the anodeelectrode is provided so as to be inserted from above into the treatmentcell fixed to a vertical rotation shaft, the treatment cell furtherincludes a conductive ring provided along the inner face thereof, andelectric current can be passed through the conductive ring from thevertical rotation shaft.

(II) In the foregoing structure (I), the anode electrode includes: ananode terminal; and an anode case for containing an anode metal forsurface treatment, which is detachably attached to the anode terminalvia screw.

(III) In the foregoing structure (II), the anode electrode is attachedto the cover body, and when the receiving tank is covered by the coverbody, the anode electrode is inserted from above into the treatmentcell.

(IV) The surface treatment liquid supply means includes: a supply pipefor supplying the surface treatment liquid in the tank to the inside ofthe treatment cell via a filter; and a return pipe for supplying thesurface treatment liquid in the tank to the inside of this tank via thefilter; thus, during an operation period, the surface treatment liquidis supplied through the supply pipe and the return pipe, and during anon-operation period, the surface treatment liquid is supplied onlythrough the return pipe.

(V) A chamber inside an apparatus main body, to which the treatment cellis attached, has a bottom face, and this bottom face is inclined so asto be lowered toward a discharge port formed at the bottom face.

(VI) A resin body, against which a lower end of a peripheral wall of thecover body abuts when the receiving tank is covered by the cover body,is provided along an inner face of a peripheral wall of the receivingtank.

(VII) A flange inclined inwardly downward is provided at the inner faceof the lower end of the peripheral wall of the cover body.

(VIII) The vertical rotation shaft is separated from the receiving tankby an inner peripheral wall of the receiving tank.

(IX) In the foregoing structure (VIII), a receiving plate, which isconnected to an upper end of the vertical rotation shaft and on whichthe treatment cell is placed, has at its lower face a peripheral wallsurrounding an upper end portion of the inner peripheral wall of thereceiving tank.

Effects of the Invention

According to the first to fourth aspects of the present invention, thefollowing effects can be achieved.

(1) The surface treatment liquid(s) can be supplied to the inside of thetreatment cell by operating the surface treatment liquid supply meanswhile rotating the treatment cell containing small objects by thevertical rotation shaft. Thus, a surface treatment can be carried out onthe small objects.

(2) Since the surface treatment apparatus includes the cover body, thesurface treatment liquid(s) can be prevented from scattering to outsideduring treatment.

Further, according to the first to fourth aspects of the presentinvention, the inner face of the cover body and/or the outer face of thetreatment cell can be cleaned by operating the first cleaning means. Inother words, the surface treatment liquid(s), scattered on the innerface of the cover body and/or the outer face of the treatment cell, canbe washed off. Accordingly, the separate collection of the surfacetreatment liquids described above can be more effectively carried out.

Furthermore, according to the second and fourth aspects of the presentinvention, the cover body can be automatically opened/closed byoperating the opening/closing means. In addition, the cover body can belowered from slightly above the receiving tank while being kept in ahorizontal state, thereby covering the receiving tank by the cover body;thus, the peripheral wall of the cover body can be relatively deeplyinserted into the receiving tank, and accordingly, the receiving tankcan be favorably covered by the cover body.

Moreover, according to the third and fourth aspects of the presentinvention, the following effects can be achieved.

(1) The surface treatment(s) can be performed by using the surfacetreatment liquid(s) in the tank(s) by operating the surface treatmentliquid supply means, and the used surface treatment liquid(s) can bereturned to the tank(s) by operating the drain means. Thus, the surfacetreatment liquid(s) can be reused.

(2) The inside of the treatment cell can be cleaned by operating thecleaning water supply means, and the cleaning water can be dischargedfrom the discharge portion while the surface treatment liquid(s) can becontained in the tank(s) by operating the drain means.

(3) By operating the drain means, the cleaning water can beautomatically discharged from the discharge portion and the surfacetreatment liquid(s) can be automatically collected in the tank(s).

(4) Since the connecting pipe is raised or lowered to connect thedischarge member with the inlets of the tank and the discharge portion,a liquid passage is ensured without interruption; accordingly, thesurface treatment liquid(s) and cleaning water can be prevented frombeing leaked to outside with certainty.

Besides, according to the fourth aspect of the present invention, theinside of the treatment cell can be cleaned by operating the cleaningwater supply means, and two types of surface treatment liquids can becontained in the respective original tanks by operating the drain means.Accordingly, after one surface treatment liquid has been used andcontained in one tank, cleaning is performed, and then another surfacetreatment liquid can be used and contained in another tank.Consequently, the respective surface treatment liquids can be collectedstrictly separately so as not to mix the surface treatment liquids witheach other.

In the foregoing structure (a), the inner face of the cover body and theouter face of the treatment cell can be cleaned with certainty.

In the foregoing structure (b), the cover body can be opened/closedautomatically. In addition, the cover body can be lifted to a positionat which the cover body does not interfere with operation(s) forattaching/detaching the treatment cell.

In the foregoing structure (c), the inner face of the discharge membercan be cleaned. Accordingly, for example, after one surface treatmentliquid has been used and collected in one tank via the discharge member,the cleaning of the inner face of the discharge member is performed bythe second cleaning means, and then another surface treatment liquid canbe used and collected in another tank via the discharge member.Consequently, the respective surface treatment liquids can be collectedstrictly separately so as not to mix the surface treatment liquids witheach other in the discharge member in particular.

In the foregoing structure (I), electric current is passed between theanode electrode and the conductive ring of the treatment cell, therebymaking it possible to perform, as a surface treatment, an electrolytictreatment such as an electroplating treatment, for example.

In the foregoing structure (II), the maintenance of the anode electrodecan be easily carried out.

In the foregoing structure (III), the attachment/detachment of the anodeelectrode can be performed simultaneously with the opening/closing ofthe cover body, and therefore, the operating efficiency can be improved.In addition, since the support means for supporting only the anodeelectrode can be eliminated, the structure of the apparatus can besimplified.

In the foregoing structure (IV), the surface treatment liquid in thetank can be returned to the inside of the tank through the filter duringnot only an operation period but also a non-operation period of thesurface treatment liquid supply means, and therefore, the surfacetreatment liquid in the tank can be constantly cleaned. Accordingly, theclean surface treatment liquid can be reused.

In the foregoing structure (V), the surface treatment liquid and/orcleaning water, dripped down on the bottom face, will flow toward thedischarge port in the chamber inside the apparatus main body, to whichthe treatment cell is attached. Accordingly, the cleaning of the bottomface can be carried out with ease.

In the foregoing structure (VI) or (VII), the surface treatment liquidand/or cleaning water can be prevented from being leaked to the outsideof the receiving tank.

In the foregoing structure (VIII), the surface treatment liquid and/orcleaning water can be prevented from being leaked toward the verticalrotation shaft.

In the foregoing structure (IX), the leakage of the surface treatmentliquid and/or cleaning water toward the vertical rotation shaft througha gap between the receiving plate and inner peripheral wall can beprevented, and the effects resulting from the foregoing structure (VIII)can be consequently achieved with more certainty.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front cross-sectional view of a surface treatment apparatusaccording to a first embodiment.

FIG. 2 is a cross-sectional view taken along the arrows II-II of FIG. 1.

FIG. 3 is a cross-sectional view taken along the arrows III-III of FIG.2.

FIG. 4 is a rear perspective view of the apparatus shown in FIG. 1.

FIG. 5 is a cross-sectional view taken along the arrows V-V of FIG. 3.

FIG. 6 is a partially enlarged view of FIG. 1.

FIG. 7 is an exploded perspective view showing an attachment structureof a treatment cell.

FIG. 8 is a plan view of a cover body in a state where it covers areceiving tank.

FIG. 9 is a cross-sectional view taken along the arrows IX-IX of FIG. 8.

FIG. 10 is a cross-sectional view taken along the arrows X-X of FIG. 8.

FIG. 11 is a cross-sectional view taken along the arrows XI-XI of FIG.8.

FIG. 12 is a partial cross-sectional view showing a first anodeelectrode and a first support means.

FIG. 13 is an enlarged cross-sectional view of the first anodeelectrode.

FIG. 14 is a plan perspective view of an arm.

FIG. 15 is an enlarged partial view of FIG. 3, showing anopening/closing means for the cover body.

FIG. 16 is a diagram viewed from the arrow XVI of FIG. 15.

FIG. 17 is a diagram viewed from the arrow XVII of FIG. 15.

FIG. 18 is a plan view of a support body of the opening/closing means.

FIG. 19 is an enlarged perspective view of principal portions of theopening/closing means.

FIG. 20 is an enlarged partial view of FIG. 3, showing a drain means.

FIG. 21 is a diagram viewed from the arrow XXI of FIG. 20.

FIG. 22 is a cross-sectional view taken along the arrow XXII-XXII ofFIG. 18.

FIG. 23 is an enlarged front cross-sectional view of the first anodeelectrode.

FIG. 24 is an exploded enlarged front cross-sectional view of the firstanode electrode.

FIG. 25 is a schematic top perspective view showing the inside of anupper chamber at a front part of an apparatus main body.

FIG. 26 is a cross-sectional view showing a state in which the coverbody is opened by the opening/closing means.

FIG. 27 is a cross-sectional view showing a state in which the coverbody is closed by the opening/closing means.

FIG. 28 is a cross-sectional view showing an operation of theopening/closing means in progress.

FIG. 29 is a top perspective view showing a state of the first anodeelectrode prior to an operation of the first support means in a firstanode electrode insertion step.

FIG. 30 is a top perspective view showing the state subsequent to FIG.29 in the first anode electrode insertion step.

FIG. 31 is a top perspective view showing the state subsequent to FIG.30 in the first anode electrode insertion step.

FIG. 32 is a top perspective view showing the state subsequent to FIG.31 in the first anode electrode insertion step.

FIG. 33 is a cross-sectional view showing a first modified example of afirst cleaning means.

FIG. 34 is a plan view of a pipe shown in FIG. 33.

FIG. 35 is a cross-sectional view showing a second modified example ofthe first cleaning means.

FIG. 36 is a diagram viewed from the arrow XXXVI of FIG. 35.

FIG. 37 is a cross-sectional view showing a third modified example ofthe first cleaning means.

FIG. 38 is a cross-sectional view showing a fourth modified example ofthe first cleaning means.

FIG. 39 is a diagram viewed from the arrow XXXIX of FIG. 38.

FIG. 40 is a plan view showing a fifth modified example of the firstcleaning means.

FIG. 41 is a perspective view showing a first modified example of theopening/closing means.

FIG. 42 is a cross-sectional view showing a state in which the coverbody is closed by the opening/closing means of FIG. 41.

FIG. 43 is a cross-sectional view showing an opening operation of thecover body, which is performed by the opening/closing means of FIG. 41.

FIG. 44 is a cross-sectional view showing an opening operationsubsequent to FIG. 43.

FIG. 45 is a cross-sectional view showing a state in which the coverbody is opened by the opening/closing means of FIG. 41.

FIG. 46 is a side view showing a second modified example of theopening/closing means.

FIG. 47 is a perspective view showing a third modified example of theopening/closing means.

FIG. 48 is a perspective view showing a fourth modified example of theopening/closing means.

FIG. 49 is a cross-sectional view showing a first modified example ofthe drain means.

FIG. 50 is a cross-sectional view showing a second modified example ofthe drain means.

FIG. 51 is a cross-sectional view showing an operating state of thedrain means of FIG. 50.

FIG. 52 is a side view showing a first modified example of an anodeelectrode support means.

FIG. 53 is a cross-sectional view showing a second modified example ofthe anode electrode support means.

FIG. 54 is a side view showing a third modified example of the anodeelectrode support means.

FIG. 55 is a perspective view of a surface treatment apparatus accordingto a second embodiment.

DESCRIPTION OF THE REFERENCE CHARACTERS

-   -   10 rotary surface treatment apparatus    -   11 treatment cell    -   112 electrode ring (conductive ring)    -   12 vertical rotation shaft    -   143 peripheral wall    -   15 receiving tank    -   154 resin body    -   155 inner peripheral wall    -   16 cover body    -   165 flange    -   21 first tank    -   22 first surface treatment liquid supply means    -   24 second tank    -   25 second surface treatment liquid supply means    -   27 third tank    -   211, 241, 271 inlet    -   221, 251 filter    -   222, 252 first supply pipe    -   223, 253 return pipe    -   224, 254 second supply pipe    -   3 drain means    -   33 connecting pipe    -   41 first anode electrode    -   411 first anode terminal    -   412 anode case    -   5 first cleaning means    -   51 slit (ejection port)    -   52 ejection port    -   53, 54 water supply passage    -   7 opening/closing means    -   71 arm    -   72 roller (rotary body)    -   73 horizontal support shaft    -   74 support body    -   75 raising and lowering means    -   76 abutment body    -   8 second cleaning means

BEST MODE FOR CARRYING OUT THE INVENTION First Embodiment

The present embodiment relates to a so-called “two-liquid type” surfacetreatment apparatus for carrying out two types of surface treatments inthe single apparatus. FIG. 1 is a front cross-sectional view of asurface treatment apparatus 10 according to the present embodiment, FIG.2 is a cross-sectional view taken along the arrows II-II of FIG. 1, FIG.3 is a cross-sectional view taken along the arrows III-III of FIG. 2,FIG. 4 is a rear perspective view of the apparatus 10 of FIG. 1, andFIG. 5 is a cross-sectional view taken along the arrows V-V of FIG. 3.The present embodiment is implemented by installing all componentswithin a single apparatus main body 100. The apparatus main body 100 canbe moved, via rollers 201 provided at its bottom face, on a floorsurface, and can be fixed onto the floor surface by stoppers 202provided at the bottom face.

As shown in FIG. 1, an upper chamber 101 at a front part of theapparatus main body 100 is provided with: a treatment cell 11; areceiving tank 15; a cover body 16; a first anode electrode 41 and apart of a first support means 43 for supporting this electrode; a firstretraction section 45; a second anode electrode 46 and a part of asecond support means 48 for supporting this electrode; and a secondretraction section 49.

As shown in FIG. 1, a lower chamber 102 at the front part of theapparatus main body 100 is provided at its center with: a verticalrotation shaft 12; and a motor 13 for driving the vertical rotationshaft 12, and is further provided at its both sides with: a remainingpart of the first support means 43; and a remaining part of the secondsupport means 48.

As shown in FIG. 2 and FIG. 3, an upper chamber 103 at a rear part ofthe apparatus main body 100 is provided at its front with anopening/closing means 7 for the cover body 16, and is provided at itsrear with two filters 221 and 251, which are laterally aligned.

As shown in FIG. 3, FIG. 4 and FIG. 5, a lower chamber 104 at the rearpart of the apparatus main body 100 is provided at its front with adrain means 3, and is provided at its rear with a first tank 21, asecond tank 24 and a third tank 27, which are laterally aligned.

As shown in FIG. 2 and FIG. 4, the upper chamber 103 and lower chamber104 at the rear part of the apparatus main body 100 is provided with: afirst surface treatment liquid supply means 22; a second surfacetreatment liquid supply means 25; and a cleaning water supply means (notshown).

Moreover, as shown in FIG. 2, a lateral chamber 105 of the apparatusmain body 100 is provided with a control section 6.

FIG. 6 is a partially enlarged view of FIG. 1. As shown in FIG. 6, thetreatment cell 11 is formed to include a non-conductive disc-like bottomplate 111, an electrode ring (conductive ring) 112 and a non-conductivehood 113, which are superposed and combined in by bolts 114. Further,the treatment cell 11 has, at its inside, a space 110 capable ofcontaining small objects serving as objects to be surface-treated. Thehood 113 has an opening 115 at its center. Furthermore, the treatmentcell 11 has a liquid flow-out means (not shown) for allowing a liquidinside the treatment cell 11 to flow out little by little from theperiphery thereof to the outside of the treatment cell 11.

As the liquid flow-out means, the following structure (a), (b) or thelike can be adopted, for example.

(a) A porous ring having a large number of through holes communicatedwith inside and outside is provided between the bottom plate 111 and theelectrode ring 112.

(b) A gap communicated with inside and outside is provided between thebottom plate 111 and the electrode ring 112.

Besides, as the above-mentioned structure (b), the following structures(b1), (b2) or the like can be adopted, for example.

(b1) A groove communicated with inside and outside is formed in thebottom plate 111.

(b2) Spacers are sandwiched between the bottom plate 111 and theelectrode ring 112 circumferentially at appropriate intervals.

The treatment cell 11 is fixed to the vertical rotation shaft 12 via anattachment/detachment means. The attachment/detachment means has: aconductive disc-like receiving plate 141 fixed onto an upper end of thevertical rotation shaft 12; and bolts 142 for fixing the treatment cell11 to the receiving plate 141. In other words, the treatment cell 11 isfixed to the vertical rotation shaft 12 by placing the cell on thereceiving plate 141 and tightening with the bolts 142. Then, the passageof electric current through the electrode ring 112 of the treatment cell11 is carried out from the vertical rotation shaft 12 via the receivingplate 141 and the bolts 142.

The receiving tank 15 is provided so as to cover, from below, thetreatment cell 11 fixed to the vertical rotation shaft 12, and is formedby a bottom wall 151 and a peripheral wall 152. The bottom wall 151 isinclined so as to be lowered toward a single discharge port 153.

The cover body 16 is provided so as to cover, from above, the receivingtank 15, and is opened/closed by the opening/closing means 7 (FIG. 3).The opening/closing means 7 will be described later. The cover body 16has an opening 161 at its center.

Moreover, an upper part of an inner face of the peripheral wall 152 ofthe receiving tank 15 is provided with a circumferentially continuouslyextending resin body 154. The resin body 154 is provided so that a lowerend 164 of a peripheral wall 163 of the cover body 16 abuts against theresin body from above when the cover body 16 is closed. Further, aninner face of the lower end 164 of the peripheral wall 163 of the coverbody 16 is provided with a flange 165 inclined inwardly downward.Furthermore, the vertical rotation shaft 12 is separated from thereceiving tank 15 by an inner peripheral wall 155 of the receiving tank15. In addition, the receiving plate 141 has, at its lower face, aperipheral wall 143 surrounding an upper end portion of the innerperipheral wall 155.

Further, as shown in an exploded perspective view of FIG. 7, two concaveportions 116 (FIG. 6) formed in the bottom plate 111 are fitted to twoprotrusions 144 formed at the receiving plate 141, thereby allowing thetreatment cell 11 to be attached to the receiving plate 141 via the twobolts 142.

FIG. 8 is a plan view of the cover body 16 in a state where it coversthe receiving tank 15, and FIG. 9 is a cross-sectional view taken alongthe arrows IX-IX of FIG. 8. The cover body 16 includes a first cleaningmeans 5. The first cleaning means 5 has a first ejection portion and asecond ejection portion for ejecting cleaning water. As shown in FIG. 8and FIG. 9, the first ejection portion includes slits (ejection ports)51 formed between a water supply passage 53, which is provided along aninner face 162 of the cover body 16 at an edge of the opening 161, andthe inner face 162 of the cover body 16, and ejects cleaning water ontothe inner face 162 of the cover body 16. Further, the second ejectionportion includes a plurality of ejection ports 52 formed at a watersupply passage 54 provided so as to be extended radially along the innerface 162 of the cover body 16, and ejects cleaning water onto an outerface 119 of the treatment cell 11. It should be noted that the watersupply passage 53 is extended from the water supply passage 54, and thewater supply passage 54 is connected to an external cleaning watersupply source (e.g., a water supply) similarly to the cleaning watersupply means described later.

Furthermore, as shown in FIG. 10 serving as a cross-sectional view takenalong the arrows X-X of FIG. 8, at an end of a water supply passage 56provided so as to be extended radially along the inner face 162 of thecover body 16, the cover body 16 has a nozzle 57 for supplying cleaningwater to the inside of the treatment cell 11. It should be noted thatthe water supply passage 56 constitutes the cleaning water supply meansdescribed later.

Moreover, as shown in FIG. 11 serving as a cross-sectional view takenalong the arrows XI-XI of FIG. 8, the cover body 16 has a level sensor58 at an edge of the opening 161. The level sensor 58 detects a liquidlevel inside the treatment cell 11, thereby detecting excess ordeficiency of a liquid amount.

FIG. 12 is a partial cross-sectional view showing the first anodeelectrode 41 and the first support means 43 for supporting thiselectrode. The first support means 43 has: a tubular arm 431 extendinglaterally; and a support body 432 for supporting the arm 431 at theother end thereof so that the arm 431 can be moved up and down, and sothat the arm 431 can be rotated within a horizontal plane. The supportbody 432 has: a tube body 433 extending longitudinally; a rotation driveportion 434 for rotating the tube body 433 around a longitudinal axis;and a cylinder drive portion 435 for moving up and down the tube body433 together with the rotation drive portion 434. The tube body 433 iscommunicated at its upper end with the arm 432 and is combinedtherewith. The tube body 433 is provided so as to be moved up and downwithin a sleeve 437 provided vertically at a bottom face 1011 of theupper chamber 101. Further, a portion of the tube body 433 moving up anddown within the sleeve 437 has an outer tube 436, i.e., has a dual-tubestructure. The rotation drive portion 434 is formed so as to rotate thetube body 433 by rack-and-pinion means. The rack is formed so as to bemoved by an air pressure. As shown in FIG. 13, the arm 431 is providedat its end with a nozzle 439 for supplying a first surface treatmentliquid to the inside of the treatment cell 11. FIG. 14 is a planperspective view of the arm 431. As shown in FIG. 12 and FIG. 14, anelectric wire 438 for passing electric current through the first anodeelectrode 41, and a supply passage 440 for supplying the first surfacetreatment liquid to the nozzle 439 are running through the inside of thetube body 433 and arm 431.

The second anode electrode 46 and the second support means 48 forsupporting this electrode also has structures similar to those of thefirst anode electrode 41 and the first support means 43 for supportingthis electrode. That is, as shown in FIG. 1, the second support means 48has an arm 471 and a support body 472. The support body 472 has: a tubebody 473 moving up and down within a sleeve 477 (FIG. 23); a rotationdrive portion 474; and a cylinder drive portion 475. The tube body 473has an outer tube 476. The arm 471 is provided at its end with a nozzlefor supplying a second surface treatment liquid to the inside of thetreatment cell 11. An electric wire for passing electric current throughthe second anode electrode 46, and a supply passage for supplying thesecond surface treatment liquid to the nozzle are running through theinside of the tube body 473 and arm 471.

FIG. 15 is an enlarged partial view of FIG. 3, showing theopening/closing means 7 for the cover body 16. FIG. 16 is a diagramviewed from the arrow XVI of FIG. 15, and FIG. 17 is a diagram viewedfrom the arrow XVII of FIG. 15. The opening/closing means 7 has: an arm71; a roller (rotary body) 72; a horizontal support shaft 73; a supportmeans 74; a raising and lowering means 75; and an abutment body 76.

In FIG. 15, the arm 71 is connected at its one end to the cover body 16,and is extended laterally from the cover body 16. The roller 72 isprovided at an upper portion of the other end of the arm 71. The roller72 is rotatably supported by a horizontal shaft 77 orthogonal to the arm71.

As shown in FIG. 17 in particular, the raising and lowering means 75has: a vertical pole 751; a cylinder drive portion 752; and two verticalslide shafts 753 and 754 arranged in parallel. The cylinder driveportion 752 is located at an upper side of the pole 751. The pole 751 islocated between the two slide shafts 753 and 754. By operating thecylinder drive portion 752, the raising and lowering means 75raises/lowers the pole 751 along the two slide shafts 753 and 754 via asupport body 740 described later.

The horizontal support shaft 73 is orthogonal to the arm 71, androtatably supports the arm 71 somewhere along the arm 71 while beingrotatably supported at a lower end portion of the pole 751. The supportmeans 74 includes the support body 740 and an adjustment bolt 7517. Thesupport body 740 is located below the horizontal support shaft 73, andis fixed at a lower end of the pole 751. Specifically, the support body740 has a form shown in FIG. 18, which is a plan view. Morespecifically, the support body 740 includes: a center portion 7511 atwhich the lower end of the pole 751 is fixed; and lateral portions 7512and 7513 through which the two slide shafts 753 and 754 pass,respectively. At the center portion 7511, horizontal portions 7311 (FIG.17) of L-shaped flanges 731 for supporting the horizontal support shaft73 is fixed. Further, the center portion 7511 has, at its portionopposite to the cover 16, a cut-out portion 7510. Furthermore, thecenter portion 7511 has a bolt hole 7518 into which the adjustment bolt7517 is fitted. The adjustment bolt 7517 can be fitted from a lower faceside of the support body 740, thereby allowing an upper-face-sideprotrusion height to be freely set.

Upper portions and lower portions of the two slide shafts 753 and 754,with the support body 740 serving as the boundary therebetween, arecovered by bellows. The abutment body 76 is provided above the other endof the arm 71. The abutment body 76 is formed so that the roller 72 ofthe arm 71, raised by a predetermined distance H while being in ahorizontal state, abuts against the abutment body from below.

FIG. 19 is a partial perspective view of the opening/closing means 7. Alower end portion of the pole 751 branches off to two parallel poleportions 7511. The L-shaped flanges 731 are connected to lower ends ofthe pole portions 7511. Further, the arm 71 is running between the twopole portions 7511. At portions of the support body 740 through whichthe slide shafts 753 and 754 pass, there are provided guide cylinders781 and 782 for preventing the support body 740 from wobbling relativeto the slide shafts 753 and 754. The guide cylinders 781 and 782 arefixed to the support body 740.

FIG. 20 is an enlarged partial view of FIG. 3, showing the drain means3. FIG. 21 is a diagram viewed from the arrow XXI of FIG. 20, and FIG.22 is a cross-sectional view taken along the arrow XXII-XXII of FIG. 20.The drain means 3 has: a receiver 31; a discharge pipe 32; a connectingpipe 33; a cylinder drive portion (raising and lowering portion) 34; anda rotation means (moving means) 35. The receiver 31 and the dischargepipe 32 constitute a discharge member. The receiver 31 is formed by abottom face 311 and a peripheral wall 312. The bottom face 311 isinclined so as to be lowered toward a discharge port 313. The dischargepipe 32 is communicated with the discharge port 313, and is fixed to thereceiver 31. The discharge pipe 32 includes an inclined portion 321 anda vertical portion 322. The connecting pipe 33 is provided so as to beconnected to a lower end portion of the vertical portion 322. Theconnecting pipe 33 is externally fitted to the vertical portion 322 soas to be slidable up and down, and is moved up and down along thevertical portion 322 by the cylinder drive portion 34. The cylinderdrive portion 34 is fixed to the receiver 31 and the discharge pipe 32via a support plate 341. The diameter of a lower end portion of theconnecting pipe 33 is set such that the lower end portion is internallyfitted to an inlet of each tank described later. The rotation means 35rotates a vertical rotation shaft 351, which is connected to therotational center of the receiver 31, via gears 358 and 359 by means ofa motor 354 (FIG. 21). The vertical rotation shaft 351 is supported atan inner wall 106 of the apparatus main body 100 via two arms 355 and356. On the other hand, as shown in FIG. 21 and FIG. 22, a first tank21, a second tank 24 and a third tank 27 are provided so as to bealigned laterally. The third tank 27 is located at the center. Further,as shown in FIG. 22, inlets 211, 271 and 241 of these three tanks areprovided so as to be located on an arc-shaped path R. This path Rcoincides with a path formed by the connecting pipe 33 when the rotationmeans 35 rotates the receiver 31 together with the discharge pipe 32 andthe connecting pipe 33. The rotation means 35 is capable of rotating thereceiver 31 so that the connecting pipe 33 is located over each of thethree inlets 211, 271 and 241. The adjustment of rotation of thereceiver 31 is performed by detecting the rotation angle of the receiver31 with the use of an encoder 357 and by adjusting the operation of themotor 354. The receiver 31 can be rotated by allowing a guide 315,provided at a peripheral face of the peripheral wall 312, to slide alonga rail 316. The rail 316 is fixed to a lower face of a top plate 1041 ofthe lower chamber 104.

The receiver 31 is provided, at the top plate 1041, with a secondcleaning means 8. The second cleaning means 8 has a nozzle 81 protrudingdownward from the top plate 1041, and ejects cleaning water toward aninner face of the receiver 31 from the nozzle 81. The nozzle 81 isconnected with a water supply passage 82, and the water supply passage82 is connected to the external cleaning water supply source similarlyto the cleaning water supply means described later.

As shown in FIG. 2 and FIG. 4, the first surface treatment liquid supplymeans 22 has: a first supply pipe 222 leading to the filter 221 from anoutlet port 212 of the first tank 21 via a pump 213; a return pipe 223leading to a return port 214 of the first tank 21 from the filter 221;and a second supply pipe 224 leading to the supply passage 440 of thefirst support means 43 from the filter 221. The first surface treatmentliquid supply means 22 uses the first supply pipe 222, the second supplypipe 224 and the return pipe 223 during an operation period, and usesonly the first supply pipe 222 and the return pipe 223 during anon-operation period.

As shown in FIG. 2 and FIG. 4, the second surface treatment liquidsupply means 25 has: a first supply pipe 252 leading to the filter 251from an outlet port 242 of the second tank 24 via a pump 243; a returnpipe 253 leading to a return port 244 of the second tank 24 from thefilter 251; and a second supply pipe 254 leading to the supply passageof the second support means 48 from the filter 251. The second surfacetreatment liquid supply means 25 uses the first supply pipe 252, thesecond supply pipe 254 and the return pipe 253 during an operationperiod, and uses only the first supply pipe 252 and the return pipe 253during a non-operation period.

The cleaning water supply means has a supply pipe (not shown) connectedto the external cleaning water supply source. This supply pipe isbranched off and connected to: the water supply passage 54 of the firstcleaning means 5; the water supply passage 56 leading to the nozzle 57of the cover body 16; and the water supply passage 82 of the secondcleaning means 8, respectively. It should be noted that connectionsbetween the supply pipe and the water supply passages 54, 56 and 82 areeach provided with a solenoid valve.

FIG. 23 is an enlarged front cross-sectional view of the first anodeelectrode 41, and FIG. 24 is an exploded enlarged front cross-sectionalview of the first anode electrode 41. The first anode electrode 41 has afirst anode terminal 411 and a first anode case 412. The first anodecase 412 is a receptacle including a mesh body made of titanium, forexample, and is capable of containing an anode metal for first surfacetreatment. At a lower end of the first anode terminal 411, a threadportion 413 is formed. On the other hand, at the center of a bottom faceof the first anode case 412, a screw portion 414 to which the threadportion 413 is screwed is formed. The thread portion 413 of the firstanode terminal 411 is screwed to the screw portion 414, therebydetachably attaching the first anode case 412 to the first anodeterminal 411. The first anode case 412 is formed so as to be covered bya lid 415. The lid 415 is provided at its center with a through hole 416through which the first anode terminal 411 passes.

The second anode electrode 46 also has a structure similar to that ofthe first anode electrode 41.

FIG. 25 is a schematic top perspective view showing the inside of theupper chamber 101 at the front part of the apparatus main body 100. Theupper chamber 101 has the bottom face 1011. At a corner of the bottomface 1011, a discharge port 1012 is formed. Further, the bottom face1011 is inclined so as to be lowered toward the discharge port 1012.Furthermore, the discharge port 1012 is communicated with an externaldischarge portion.

Next, how the surface treatment apparatus 10 with the above-describedstructure operates will be described in the order of steps.

Hereinafter, the description will be made about the case where two typesof surface treatments, including a first electroplating treatment and asecond electroplating treatment, are carried out by way of example.

First, the following preparations are made before the apparatus 10 isoperated.

(1) A first plating treatment liquid is put into the first tank 21, anda second plating treatment liquid is put into the second tank 24.

(2) Small objects serving as objects to be treated are charged into thetreatment cell 11.

(3) The treatment cell 11 containing the small objects is fixed to thevertical rotation shaft 12 via the attachment/detachment means.

Then, the apparatus 10 is operated. Upon operation of the apparatus 10,the following steps are carried out in sequence.

<1> Cover Body Closing Operation Step

First, the opening/closing means 7 is operated so that the cover body 16covers the receiving tank 15 from above.

Prior to the operation, the cover body 16 is in a state shown in FIG.26, i.e., in an open state. Upon operation of the apparatus 10, theopening/closing means 7 is operated so that the cover body 16 covers thereceiving tank 15 from above and enters a state shown in FIG. 27, i.e.,a closed state.

Specifically, the following operations are performed. In theopening/closing means 7 in the state shown in FIG. 26, the pole 751 hasbeen raised together with the horizontal support shaft 73 and thesupport body 740, the roller 72 has abutted against the abutment body 76from below, and the arm 71 has been inclined with a portion thereofadjacent to the roller 72 lowered. The arm 71 passes through the cut-outportion 7510 of the support body 740 to incline. In this state, uponoperation of the opening/closing means 7, the pole 751 is loweredtogether with the horizontal support shaft 73 and the support body 740,and the arm 71 rotates around the horizontal support shaft 73 togradually enter a horizontal state. Then, as shown in FIG. 28, at theinstant when the arm 71 abuts against the adjustment bolt 7517 fromabove, the rotation of the arm 71 is stopped, and concurrentlytherewith, the cover body 16 enters a horizontal state. Thereafter, thepole 751 is further lowered together with the horizontal support shaft73 and the support body 740, and concurrently therewith, the cover body16 is lowered while being kept in the horizontal state, thereby coveringthe receiving tank 15 from above as shown in FIG. 27.

<2> First Cleaning Step

Next, the motor 13, the cleaning water supply means, the first cleaningmeans 5, and the second cleaning means 8 are operated. It should benoted that the connecting pipe 33 of the drain means 3 is connected tothe inlet 271 of the third tank 27 at this point. The third tank 27serves to contain the used cleaning water, and communicates with theexternal discharge portion.

Upon operation of the cleaning water supply means, the solenoid valve isopened to supply the cleaning water to the water supply passage 56 fromthe supply pipe connected to the external cleaning water supply source,thereby supplying the cleaning water from the nozzle 57 to the inside ofthe rotating treatment cell 11. The supplied cleaning water isdischarged from the treatment cell 11 through the liquid flow-out meanswhile the cleaning water washes the inside of the treatment cell 11.Thus, the inner face of the treatment cell 11 and the small objects arecleaned.

Upon operation of the first cleaning means 5, the solenoid valve isopened to supply the cleaning water to the water supply passage 54 fromthe above-mentioned supply pipe, and the cleaning water is ejected fromthe slits 51 and the ejection ports 52 under the situation in which thetreatment cell 11 is rotating. Thus, the inner face 162 of the coverbody 16 and the outer face 119 of the treatment cell 11 are cleaned.

Upon operation of the second cleaning means 8, the solenoid valve isopened to supply the cleaning water to the water supply passage 82 fromthe above-mentioned supply pipe, and the cleaning water is ejected fromthe nozzle 81. Thus, the inner face of the receiver 31 is cleaned.

Then, when the cleaning has been carried out for a certain period oftime, the cleaning water supply means, the first cleaning means 5, andthe second cleaning means 8 stop the operations thereof. On the otherhand, the treatment cell 11 will be rotated for a while. Thus, thecleaning water remaining inside the treatment cell 11 is discharged fromthe treatment cell 11 through the liquid flow-out means.

The cleaning water, which has been discharged from the treatment cell11, and the cleaning water, which has cleaned the inner face 162 of thecover body 16 and the outer face 119 of the treatment cell 11, arereceived by the receiving tank 15, flow into the third tank 27 from thedischarge port 153 via the receiver 31 and the discharge pipe 32, andfurther flow out to the external discharge portion. Furthermore, thecleaning water, which has cleaned the inner face of the receiver 31,also flows into the third tank 27 via the discharge pipe 32, and furtherflows out to the external discharge portion.

<3> Drain Means First Operational Step

Next, the drain means 3 is operated. More specifically, the receiver 31is rotated so that the connecting pipe 33 is located above the inlet 211of the first tank 21, lowered by the cylinder drive portion 34, andconnected to the inlet 211.

<4> First Anode Electrode Insertion Step

Next, the first support means 43 is operated. It should be noted thatprior to the operation of the first support means 43, the first anodeelectrode 41 is in a state in which it is retracted into the firstretraction section 45 as shown in FIG. 29.

Upon operation of the first support means 43, the cylinder drive portion435 raises the tube body 433. Thus, as shown in FIG. 30, the arm 431 israised together with the first anode electrode 41, and the first anodeelectrode 41 gets out upward from the first retraction section 45. Next,the rotation drive portion 434 rotates the tube body 433 by apredetermined distance in the direction indicated by the arrow of FIG.30. Thus, the arm 431 is rotated together with the first anode electrode41, and the first anode electrode 41 is located above the opening 161 ofthe cover body 16 as shown in FIG. 31. Then, the cylinder drive portion435 lowers the tube body 433. Thus, as shown in FIG. 32, the first anodeelectrode 41 is inserted into the treatment cell 11.

<5> First Electroplating Treatment Step

Next, the motor 13 and the first surface treatment liquid supply means22 are operated while electric current is passed through the electrodering 112 of the treatment cell 11.

Upon operation of the first surface treatment liquid supply means 22,the first plating treatment liquid in the first tank 21 flows into thetreatment cell 11 from the nozzle 439 via the first supply pipe 222, thefilter 221, the second supply pipe 224 and the supply passage 440.Meanwhile, at this point, the treatment cell 11 is rotating, and thefirst plating treatment liquid is discharged from the treatment cell 11little by little through the liquid flow-out means.

On the other hand, in the treatment cell 11, electricity flows betweenthe first anode electrode 41 and the electrode ring 112 via the firstplating treatment liquid, and the small objects, brought into contactwith the electrode ring 112 by centrifugal force resulting from therotation of the treatment cell 11, are subjected to a plating treatmentwith the use of the first plating treatment liquid. Since the treatmentcell 11 is rotated while the rotation thereof is repeatedly changedbetween forward and reverse directions, the small objects are evenlybrought into contact with the electrode ring 112; accordingly, theplating treatment is uniformly performed on all the small objects.

Then, the first surface treatment liquid supply means 22 stops theoperation thereof after having performed the above-described platingtreatment for a certain period of time. On the other hand, the treatmentcell 11 will be rotated for a while. Thus, the first plating treatmentliquid remaining inside the treatment cell 11 is entirely dischargedfrom the treatment cell 11 through the liquid flow-out means.

The first plating treatment liquid, which has been discharged from thetreatment cell 11, is received by the receiving tank 15, falls down onthe receiver 31 from the discharge port 153, and flows into the firsttank 21 via the discharge pipe 32 and the inlet 211. In other words, thedischarged first plating treatment liquid is returned to the first tank21.

It should be noted that during the operation period and non-operationperiod of the first surface treatment liquid supply means 22, the firstplating treatment liquid in the first tank 21 is returned to the firsttank 21 via the first supply pipe 222, the filter 221 and the returnpipe 223. Accordingly, upon operation of the apparatus 10, the firstplating treatment liquid in the first tank 21 is constantly cleaned bythe filter 221.

<6> First Anode Electrode Retraction Step

Next, the first support means 43 is operated in a manner opposite to thefirst anode electrode insertion step described above. Specifically, uponoperation of the first support means 43 in the state shown in FIG. 32,the cylinder drive portion 435 raises the tube body 433. Thus, as shownin FIG. 31, the arm 431 is raised together with the first anodeelectrode 41, and the first anode electrode 41 is located above theopening 161 of the cover body 16. Next, the rotation drive portion 434rotates the tube body 433 by a predetermined distance in the directionindicated by the arrow of FIG. 31. Thus, the arm 431 is rotated togetherwith the first anode electrode 41, and the first anode electrode 41 islocated above the first retraction section 45 as shown in FIG. 30. Then,the cylinder drive portion 435 lowers the tube body 433. Thus, as shownin FIG. 29, the first anode electrode 41 is retracted into the firstretraction section 45.

<7> Drain Means Second Operational Step

Next, the drain means 3 is operated. More specifically, the receiver 31is rotated so that the connecting pipe 33 is located above the inlet 271of the third tank 27, lowered by the cylinder drive portion 34, andconnected to the inlet 271.

<8> Second Cleaning Step

Next, the motor 13, the cleaning water supply means, the first cleaningmeans 5, and the second cleaning means 8 are operated, therebyperforming operations similar to those of the above-described firstcleaning step.

<9> Drain Means Third Operational Step

Next, the drain means 3 is operated. More specifically, the receiver 31is rotated so that the connecting pipe 33 is located above the inlet 241of the second tank 24, lowered by the cylinder drive portion 34, andconnected to the inlet 241.

<10> Second Anode Electrode Insertion Step

Next, the second support means 48 is operated. It should be noted thatprior to the operation of the second support means 48, the second anodeelectrode 46 is in a state in which it is retracted into the secondretraction section 49.

The second support means 48 is operated similarly to the first supportmeans 43. Specifically, upon operation of the second support means 48, acylinder drive portion 485 raises a tube body 483. Thus, an arm 481 israised together with the second anode electrode 46, and the second anodeelectrode 46 gets out upward from the second retraction section 49.Next, a rotation drive portion 484 rotates the tube body 483 by apredetermined distance. Thus, the arm 481 is rotated together with thesecond anode electrode 46, and the second anode electrode 46 is locatedabove the opening 161 of the cover body 16. Then, the cylinder driveportion 485 lowers the tube body 483. Thus, the second anode electrode46 is inserted into the treatment cell 11.

<11> Second Electroplating Treatment Step

Next, the motor 13 and the second surface treatment liquid supply means25 are operated while electric current is passed through the electrodering 112 of the treatment cell 11.

Upon operation of the second surface treatment liquid supply means 25,the second plating treatment liquid in the second tank 24 flows into thetreatment cell 11 from the nozzle 439 via the first supply pipe 252, thefilter 251, the second supply pipe 254 and the supply passage 440.Meanwhile, at this point, the treatment cell 11 is rotating, and thesecond plating treatment liquid is discharged from the treatment cell 11little by little through the liquid flow-out means.

On the other hand, in the treatment cell 11, electricity flows betweenthe second anode electrode 46 and the electrode ring 112 via the secondplating treatment liquid, and the small objects, brought into contactwith the electrode ring 112 by centrifugal force resulting from therotation of the treatment cell 11, are subjected to a plating treatmentwith the use of the second plating treatment liquid. Since the treatmentcell 11 is rotated while the rotation thereof is repeatedly changedbetween forward and reverse directions, the small objects are evenlybrought into contact with the electrode ring 112; accordingly, theplating treatment is uniformly performed on all the small objects.

Then, the second surface treatment liquid supply means 25 stops theoperation thereof after having performed the above-described platingtreatment for a certain period of time. On the other hand, the treatmentcell 11 will be rotated for a while. Thus, the second plating treatmentliquid remaining inside the treatment cell 11 is entirely dischargedfrom the treatment cell 11 through the liquid flow-out means.

The second plating treatment liquid, which has been discharged from thetreatment cell 11, is received by the receiving tank 15, falls down onthe receiver 31 from the discharge port 153, and flows into the secondtank 24 via the discharge pipe 32 and the inlet 241. In other words, thedischarged second plating treatment liquid is returned to the secondtank 24.

It should be noted that during the operation period and non-operationperiod of the second surface treatment liquid supply means 25, thesecond plating treatment liquid in the second tank 24 is returned to thesecond tank 24 via the first supply pipe 252, the filter 251 and thereturn pipe 253. Accordingly, upon operation of the apparatus 10, thesecond plating treatment liquid in the second tank 24 is constantlycleaned by the filter 251.

<12> Second Anode Electrode Retraction Step

Next, the second support means 48 is operated in a manner opposite tothe second anode electrode insertion step described above. Specifically,upon operation of the second support means 48, the cylinder driveportion 485 raises the tube body 483. Thus, the arm 481 is raisedtogether with the second anode electrode 46, and the second anodeelectrode 46 is located above the opening 161 of the cover body 16.Next, the rotation drive portion 484 rotates the tube body 483 by apredetermined distance. Thus, the arm 481 is rotated together with thesecond anode electrode 46, and the second anode electrode 46 is locatedabove the second retraction section 49. Then, the cylinder drive portion485 lowers the tube body 483. Thus, the second anode electrode 46 isretracted into the second retraction section 49.

<13> Drain Means Fourth Operational Step

Next, the drain means 3 is operated. More specifically, the receiver 31is rotated so that the connecting pipe 33 is located above the inlet 271of the third tank 27, lowered by the cylinder drive portion 34, andconnected to the inlet 271.

<14> Third Cleaning Step

Next, the motor 13, the cleaning water supply means, the first cleaningmeans 5, and the second cleaning means 8 are operated, therebyperforming operations similar to those of the above-described firstcleaning step.

<15> Cover Body Opening Operation Step

Next, upon operation of the opening/closing means 7, the cover body 16gets away from the receiving tank 15. More specifically, upon operationof the opening/closing means 7 in the state shown in FIG. 27, the pole751 is raised in conjunction with the arm 71 together with thehorizontal support shaft 73 and the support body 740, and the roller 72is also raised. At this point, the cover body 16 is also gotten awayfrom the receiving tank 15 and raised while being kept in the horizontalstate. Upon raising of the pole 751 by a distance H, as shown in FIG.28, the roller 72 abuts against the abutment body 76 from below. Then,upon further raising of the pole 751, the roller 72 rotates whileabutting against the abutment body 76, and the arm 71 will be inclinedupward using the roller 72 as a supporting point. Thus, the cover body16 enters the state shown in FIG. 26, i.e., the open state. It should benoted that the arm 71 passes through the cut-out portion 7510 of thesupport body 740 to incline.

Then, the operation of the apparatus 10 is stopped.

Thereafter, the treatment cell 11 containing the small objects isdetached from the vertical rotation shaft 12 via theattachment/detachment means. Then, the small objects are taken out fromthe treatment cell 11 and dried.

Thus, a double-layer plating film can be formed on each small object. Alower-layer plating film is formed with the use of the first platingtreatment liquid, and an upper-layer plating film is formed with the useof the second plating treatment liquid. For example, if the firstplating treatment liquid is a nickel plating liquid, the lower-layerplating film is a nickel film, and if the second plating treatmentliquid is a tin plating liquid, the upper-layer plating film is a tinfilm.

The apparatus 10 with the above-described structure can achieve thefollowing operational effects.

(1) In the first electroplating treatment step, the first electroplatingtreatment can be performed on the small objects, and in the secondelectroplating treatment step, the second electroplating treatment canbe performed on the small objects on which the first electroplatingtreatment has been performed. Accordingly, a plating film including twolayers can be formed on each small object.

(2) In the second cleaning step, the inner face of the treatment cell 11and the small objects can be cleaned by operating the cleaning watersupply means, the inner face 162 of the cover body 16 and the outer face119 of the treatment cell 11 can be cleaned by operating the firstcleaning means 5, and the inner face of the receiver 31 can be cleanedby operating the second cleaning means 8. Hence, after the first platingtreatment liquid has been collected in the first tank 21, the firstplating treatment liquid can be discharged by being cleanly washed offfrom the inside of the treatment cell 11, the inner face 162 of thecover body 16, the outer face 119 of the treatment cell 11, and theinner face of the receiver 31. Accordingly, in the second platingtreatment step, the second plating treatment liquid can be collected inthe second tank 24 strictly separately so as not to mix the secondplating treatment liquid with the first plating treatment liquid.

It should be noted that in the second cleaning step, the inner face 162of the cover body 16 and the outer face 119 of the treatment cell 11 arealso cleaned by the first cleaning means 5, and therefore, the scatteredfirst plating treatment liquid can be cleanly washed off. Further, sincethe treatment cell 11 is cleaned while being rotated, the cleaning waterblown off due to this rotation is hit on the inner face 162 of the coverbody 16 and the inner face of the receiving tank 15, thus making itpossible to cleanly wash off the scattered first plating treatmentliquid. Accordingly, the separate collection of the first platingtreatment liquid and the second plating treatment liquid can beeffectively carried out. Moreover, since the inner face of the receiver31 is also cleaned by the second cleaning means 8, the first platingtreatment liquid adhered to the inner face of the receiver 31 can becleanly washed off; accordingly, the separate collection of the firstplating treatment liquid and the second plating treatment liquid can bemore effectively carried out.

(3) In the first electroplating treatment step, the treatment isperformed using the first plating treatment liquid in the first tank 21by operating the first surface treatment liquid supply means 22, and theconnecting pipe 33 is connected to the inlet 211 of the first tank 21 bythe drain means first operational step, thus making it possible toreturn the used first plating treatment liquid to the first tank 21. Asa result of this, the first plating treatment liquid can be reused.Further, in the second electroplating treatment step, the treatment isperformed using the second plating treatment liquid in the second tank24 by operating the second surface treatment liquid supply means 25, andthe connecting pipe 33 is connected to the inlet 241 of the second tank24 by the drain means third operational step, thus making it possible toreturn the used second plating treatment liquid to the second tank 24.As a result of this, the second plating treatment liquid can be reused.

(4) Since the apparatus includes the cover body 16, the first platingtreatment liquid can be prevented from scattering in the firstelectroplating treatment step, the second plating treatment liquid canbe prevented from scattering in the second electroplating treatmentstep, and the cleaning water can be prevented from scattering in thefirst to third cleaning steps.

(5) The cover body 16 in the state where it covers the receiving tank 15abuts, at the lower end 164 of the peripheral wall 163, against theresin body 154. Accordingly, the surface treatment liquids and/or thecleaning water can be prevented from being leaked to the outside of thereceiving tank 15.

(6) The cover body 16 has the flange 165 at the inner face of the lowerend 164 of the peripheral wall 163. Accordingly, the surface treatmentliquids and/or the cleaning water can be prevented from being splashedon a region at which the peripheral wall 163 of the cover body 16 andthe peripheral wall 152 of the receiving tank 15 are overlapped. Hence,the surface treatment liquids and/or the cleaning water can be preventedfrom being leaked to the outside of the receiving tank 15.

(7) Since the resin body 154 and the flange 165 are both provided, theflange 165 prevents the cleaning water, falling down along the innerface 162 of the cover body 16, from being adhered to a region at whichthe resin body 154 and the lower end 164 of the cover body 16 abutagainst each other. Accordingly, the cleaning water and/or the surfacetreatment liquids can be prevented, with more certainty, from flowingout to the outside of the cover body 16 and the receiving tank 15.

(8) Since the vertical rotation shaft 12 is separated from the receivingtank 15 by the inner peripheral wall 155 of the receiving tank 15, thesurface treatment liquids and/or the cleaning water can be preventedfrom being leaked toward the vertical rotation shaft 12. Besides, sincethe receiving plate 141 connected to the upper end of the verticalrotation shaft 12 has, at its lower face, the peripheral wall 143surrounding the upper end portion of the inner peripheral wall 155, thesurface treatment liquids and/or the cleaning water can be preventedfrom being leaked toward the vertical rotation shaft 12 through a gap156 (FIG. 6) between the receiving plate 141 and the inner peripheralwall 155; accordingly, the leakage toward the vertical rotation shaft 12can be prevented with certainty.

(9) Since electric current can be passed between the first anodeelectrode 41 and the electrode ring 112 of the treatment cell 11, thefirst electroplating treatment can be carried out. Further, sinceelectric current can be passed between the second anode electrode 46 andthe electrode ring 112 of the treatment cell 11, the secondelectroplating treatment can be carried out. Accordingly, two types ofelectroplating treatments can be carried out.

(10) In the cover body closing operation step, the cover body 16 can beautomatically closed by operating the opening/closing means 7. Further,in the cover body opening operation step, the cover body 16 can beautomatically opened by operating the opening/closing means 7. Besides,in the cover body opening operation step, the cover body 16 can beopened to an upwardly inclined high position, and therefore, the coverbody 16 can be located at a position that does not interfere withoperation(s) for attaching/detaching the treatment cell 11 to/from thevertical rotation shaft 12.

(11) In the cover body closing operation step, the cover body 16 islowered from slightly above the receiving tank 15 while being kept inthe horizontal state, thereby covering the receiving tank 15. Thus, theperipheral wall 163 of the cover body 16 can be relatively deeplyinserted into the receiving tank 15. Accordingly, the receiving tank 15can be covered by the cover body 16 with more certainty, and thetreatment liquids and/or cleaning water can be prevented from scatteringto the outside.

(12) In the cover body closing operation step and the cover body openingoperation step, the cover body 16 enters the horizontal state slightlyabove the receiving tank 15, and therefore, the level sensor 58 can beprevented from colliding with an edge of the opening 115 of thetreatment cell 11 when the cover body 16 is inclined while beingraised/lowered.

(13) In the first electroplating treatment step, during the operationperiod and non-operation period of the first surface treatment liquidsupply means 22, the first plating treatment liquid in the first tank 21can be returned to the inside of the first tank 21 through the filter221. Accordingly, the first plating treatment liquid in the first tank21 can be cleaned. Furthermore, in the second electroplating treatmentstep, during the operation period and non-operation period of the secondsurface treatment liquid supply means 25, the second plating treatmentliquid in the second tank 24 can be returned to the inside of the secondtank 24 through the filter 251. Accordingly, the second platingtreatment liquid in the second tank 24 can be cleaned. Consequently, theclean surface treatment liquids can be reused.

(14) In the first anode electrode insertion step, the first anodeelectrode 41 can be automatically inserted into the treatment cell 11 byoperating the first support means 43. Furthermore, in the first anodeelectrode retraction step, the first anode electrode 41 can beautomatically retracted into the first retraction section 45 byoperating the first support means 43. Therefore, when the first anodeelectrode 41 is not used, the first anode electrode 41 can be preventedfrom interfering with attachment/detachment operation(s) and the likefor the treatment cell 11 because the first anode electrode 41 can beretracted into the first retraction section 45, and furthermore,peripheral regions of the treatment cell 11 can be prevented from beingcontaminated by the first plating treatment liquid adhered to the firstanode electrode 41.

(15) In the second anode electrode insertion step, the second anodeelectrode 46 can be automatically inserted into the treatment cell 11 byoperating the second support means 48. Further, in the second anodeelectrode retraction step, the second anode electrode 46 can beautomatically retracted into the second retraction section 49 byoperating the second support means 48. Therefore, when the second anodeelectrode 46 is not used, the second anode electrode 46 can be preventedfrom interfering with attachment/detachment operation(s) and the likefor the treatment cell 11 because the second anode electrode 46 can beretracted into the second retraction section 49, and furthermore,peripheral regions of the treatment cell 11 can be prevented from beingcontaminated by the second plating treatment liquid adhered to thesecond anode electrode 46.

(16) Since the first anode electrode 41 is provided by detachablyattaching the first anode case 412 to the first anode terminal 411, themaintenance of the first anode electrode 41 can be easily carried out byremoving the first anode case 412 therefrom. The same goes for thesecond anode electrode 46.

(17) In the upper chamber 101 of the apparatus main body 100, theplating treatment liquids and/or cleaning water, dripped down on thebottom face 1011, is allowed to flow toward the discharge port 1012.Accordingly, the cleaning of the bottom face 1011 can be carried outwith ease.

It should be noted that in the first electroplating treatment step andthe second electroplating treatment step, a so-called “defoamingoperation” is preferably performed. In general, if a surface treatmentliquid contains a surface-active agent, bubbles are generated during asurface treatment, which might cause trouble in the surface treatment.Therefore, when generation of bubbles is recognized, in the name of the“defoaming operation”, the passage of electric current through thetreatment cell 11 is stopped and the rotation of the treatment cell 11is slowed down while the supply of the surface treatment liquid iscontinued, thereby causing the overflow of the surface treatment liquidfrom the treatment cell 11 together with the bubbles. Thus, the surfacetreatment can be favorably carried out without being hampered by thebubbles.

It should be noted that in the surface treatment apparatus of thepresent embodiment, the following modified structure(s) may be adopted.

<Modified Structure of First Cleaning Means 5>

(A) A first modified example will be described. As shown in FIG. 33 andFIG. 34, the first cleaning means 5 is formed by using a single pipe 59.FIG. 34 is a plan view of the pipe 59 shown in FIG. 33. It should benoted that in both of the diagrams, the cleaning water supply means iseliminated. Specifically, the pipe 59 includes: a circular portion 591equivalent to the water supply passage 53 shown in FIG. 8; and astraight portion 592 equivalent to the water supply passage 54 shown inFIG. 8. Further, the circular portion 591 is provided, in the vicinityof an upper region of the longitudinal cross section, with a largenumber of ejection ports 5911 (equivalent to the slits 51), and thestraight portion 592 is provided, at a lowermost region of thelongitudinal cross section, with one or more ejection ports 5921(equivalent to the ejection ports 52).

In this structure, the cleaning water, which has been supplied to thepipe 59 through the supply pipe connected to the external cleaning watersupply source, is ejected onto the inner face 162 of the cover body 16from the ejection ports 51, and is ejected onto the outer face 119 ofthe treatment cell 11 from the ejection port(s) 52.

Also in this structure, operational effects similar to those of thefirst cleaning means 5 shown in FIG. 8 to FIG. 10 can be achieved. Inaddition, the structure of the first cleaning means 5 can be simplified.

(B) A second modified example will be described. As shown in FIG. 35 andFIG. 36, the first cleaning means 5 further has a third ejectionportion. FIG. 36 is a diagram viewed from the arrow XXXVI of FIG. 35.The third ejection portion includes ejection ports 611 formed in a watersupply passage 61 provided along an outer peripheral edge of the coverbody 16.

In this structure, the cleaning water, which has been supplied to thewater supply passage 61 through the supply pipe connected to theexternal cleaning water supply source, is ejected onto the inner face ofthe peripheral wall 163 of the cover body 16 from the ejection ports611.

Also in this structure, operational effects similar to those of thefirst cleaning means 5 shown in FIG. 8 to FIG. 10 can be achieved. Inaddition, the inner face of the peripheral wall 163 of the cover body 16can be cleaned with certainty.

(C) A third modified example will be described. As shown in FIG. 37, thefirst cleaning means 5 has a plurality of the water supply passages 54.Each water supply passage 54 extends radially from the water supplypassage 53. A plurality of the ejection ports 52 are formed in eachwater supply passage 54.

In this structure, the cleaning water, which has been supplied throughthe supply pipe connected to the external cleaning water supply source,flows into each water supply passage 54, and is ejected onto the outerface 119 of the treatment cell 11 from the ejection ports 52 of eachwater supply passage 54.

Also in this structure, operational effects similar to those of thefirst cleaning means 5 shown in FIG. 8 to FIG. 10 can be achieved. Inaddition, the outer face 119 of the treatment cell 11 can be effectivelycleaned.

(D) A fourth modified example will be described. As shown in FIG. 38 andFIG. 39, the first cleaning means 5 has the water supply passage 54provided so as to surround the water supply passage 53 from the radialoutside of the cover body 16. FIG. 39 is a diagram viewed from the arrowXXXIX of FIG. 38.

In this structure, the cleaning water, which has been supplied throughthe supply pipe connected to the external cleaning water supply source,is ejected onto the outer face 119 of the treatment cell 11 from theejection ports 52 of the circumferentially extending water supplypassage 54.

Also in this structure, operational effects similar to those of thefirst cleaning means 5 shown in FIG. 8 to FIG. 10 can be achieved. Inaddition, the outer face 119 of the treatment cell 11 can be cleaned allalong its circumference with certainty.

(E) A fifth modified example will be described. In this example, thecleaning water supply means and the first cleaning means are integrallyformed. As shown in FIG. 40, the water supply passages 53 and 54 of thefirst cleaning means 5 are connected to the nozzles 57 of the cleaningwater supply means.

In this structure, the cleaning water, which has been supplied throughthe supply pipe connected to the external cleaning water supply source,is ejected onto the inner face 162 of the cover body 16 from the slits51, ejected onto the outer face 119 of the treatment cell 11 from theejection ports 52, and injected into the treatment cell 11 from thenozzles 57.

Also in this structure, operational effects similar to those of thefirst cleaning means 5 shown in FIG. 8 to FIG. 10 can be achieved. Inaddition, since the cleaning water supply means can be eliminated, thestructure of the apparatus can be simplified.

It should be noted that in the foregoing examples, only water issupplied as the cleaning water, but high-pressure air and water can bemixed with each other and ejected. Thus, since the water and air gushout due to the pressure of the air, higher cleaning effects areobtained.

<Modified Example of Opening/Closing Means 7>

(A) A first modified example will be described. FIG. 41 is a perspectiveview of the opening/closing means 7, and FIG. 42 to FIG. 45 are lateralcross-sectional views sequentially showing operations of theopening/closing means. This opening/closing means 7 also has: the arm71; the roller (rotary body) 72; the horizontal support shaft 73; thesupport means; the raising and lowering means 75; and the abutment body.

In FIG. 42, the arm 71 includes: a front arm portion 711 extendinglaterally from the cover body 16; and a rear arm portion 712 extendingupward so as to be orthogonal to the front arm portion 711. The roller72 is provided at an upper end of the rear arm portion 712. The roller72 is supported so as to be orthogonal to the rear arm portion 712 andso as to be rotatable around a horizontal axis.

The raising and lowering means 75 has: the vertical pole 751; thecylinder drive portion 752; and the two vertical slide shafts 753 and754 arranged in parallel. The cylinder drive portion 752 is located at alower side of the pole 751. The pole 751 is located between the twoslide shafts 753 and 754. By operating the cylinder drive portion 752,the raising and lowering means 75 raises/lowers the pole 751 along thetwo slide shafts 753 and 754 via the horizontal support shaft 73.

The horizontal support shaft 73 is orthogonal to the arm 71, rotatablysupports the arm 71 at an intersection portion of the front arm portion711 and the rear arm portion 712, and is rotatably supported at upperend portion of the pole 751. Further, the horizontal support shaft 73 isextended to the slide shafts 753 and 754 on both sides, and is slidablyconnected to the slide shafts 753 and 754.

The pole 751 is provided, on both sides thereof, with frame bodies 78each having a vertical wall 781 and a horizontal wall 782. In otherwords, the two frame bodies 78 are provided. On the other hand, theroller 72 is extended from the upper end of the rear arm portion 712 tothe frame bodies 78 on both sides. The vertical walls 781 are providedso as to establish a positional relationship in which the front armportion 711 becomes horizontal when the roller 72 abuts against thevertical walls from behind. The horizontal walls 782 are extendedrearward from the vertical walls 781. Each horizontal wall 782 isprovided at a height at which the roller 72 abuts against the horizontalwall from below when the front arm portion 711 is raised by apredetermined distance H (FIG. 42) while being kept in the horizontalstate. The vertical walls 781 constitute the support means for thisopening/closing means 7, and the horizontal walls 782 constitute theabutment body for this opening/closing means 7.

The opening/closing means 7 with the above-described structure carriesout an opening operation as follows.

Upon operation of the opening/closing means 7 in the state where thecover body 16 is closed, i.e., in the state shown in FIG. 42, the pole751 is raised in conjunction with the arm 71 together with thehorizontal support shaft 73, and the roller 72 is also raised as shownin FIG. 43. At this point, the cover body 16 is also gotten away fromthe receiving tank 15 and raised while being kept in the horizontalstate. Upon raising of the pole 751 by the distance H, the roller 72abuts against the horizontal walls 782 from below. Then, as shown inFIG. 44, upon further raising of the pole 751, the roller 72 is movedbackward along the horizontal walls 782 while being rotated, and thefront arm portion 711 will be inclined upward using the horizontalsupport shaft 73 as a supporting point. Thus, the cover body 16 entersthe state shown in FIG. 45, i.e., an open state, and abuts against asupport member 79 provided at a backward position, thereby preventingthe cover body 16 from toppling backward.

Also in the opening/closing means 7 with the foregoing structure,operational effects similar to those of the opening/closing means 7shown in FIG. 15 can be achieved.

(B) A second modified example will be described. FIG. 46 is a side viewof the opening/closing means 7. This opening/closing means 7 has the arm71 and the raising and lowering means 75.

The raising and lowering means 75 has: a chain 755 running up and down;a chain drive means 756; and a slide shaft 757 extending up and down.The chain 755 runs between an upper sprocket 7551 and a lower sprocket7552.

The arm 71 is extended laterally from the cover body 16, and is providedso as to be slidable, at its other end portion, along the slide shaft757 via a bearing 713. Further, the bearing 713 is connected to thechain 755.

In this opening/closing means 7, upon operation of the chain drive means756, the chain 755 is moved up/down, and concurrently therewith, the arm71 is moved up/down along the slide shaft 757; as a result, the coverbody 16 is moved up/down while being kept in the horizontal state. Thus,the opening/closing of the cover body 16 is carried out.

Also in the opening/closing means 7 with the foregoing structure,operational effects similar to those of the opening/closing means 7shown in FIG. 15 can be achieved. In addition, the structure of theopening/closing means 7 can be extremely simplified.

(C) A third modified example will be described. FIG. 47 is a perspectiveview of the opening/closing means 7. This opening/closing means 7 hasthe arm 71, the raising and lowering means 75 and a lateral movementmeans 91.

The lateral movement means 91 has a lateral movement body 911 and a rail912. The rail 912 extends in the direction orthogonal to the arm 71. Thelateral movement body 911 is provided so as to be moved along the rail912 by a drive source (not shown).

Above the lateral movement body 911, the raising and lowering means 75has: the pole 751 extending up and down; the cylinder drive means 752for moving up and down the pole 751; and the slide shaft 757 extendingup and down. An upper end of the pole 751 is connected to the arm 71 atsome midpoint thereof.

The arm 71 is extended laterally from the cover body 16, and is providedso as to be slidable, at its other end portion, along the slide shaft757 via the bearing 713.

An opening operation of this opening/closing means 7 will be carried outas follows. Specifically, upon operation of the cylinder drive means752, the arm 71 is raised by a predetermined distance (e.g., theabove-mentioned distance H) along the slide shaft 757, and as a result,the cover body 16 is raised by the above-mentioned predetermineddistance while being kept in the horizontal state. Thereafter, thelateral movement means 91 is operated, and the lateral movement body 91is moved along the rail 912. Thus, the arm 71 is moved together with thecover body 16, and the cover body 16 is moved laterally from above thetreatment cell 11. In other words, the cover body 16 enters an openstate. It should be noted that a closing operation is carried out in amanner opposite to this opening operation.

Also in the opening/closing means 7 with the foregoing structure,operational effects similar to those of the opening/closing means 7shown in FIG. 15 can be achieved. In addition, since the cover body 16can be completely moved away from the treatment cell 11, the reliableopen state can be realized.

(D) A fourth modified example will be described. FIG. 48 is aperspective view of the opening/closing means 7. This opening/closingmeans 7 has the arm 71, the raising and lowering means 75, and arotation means 92.

The raising and lowering means 75 has: the pole 751 extending up anddown; the cylinder drive means 752 for moving up and down the pole 751;the slide shaft 757 extending up and down; and a raising and loweringplate 758. The pole 751 is fixed, at its upper end, to a lower face ofthe raising and lowering plate 758. The raising and lowering plate 758is provided so as to be moved up and down along the slide shaft 757.

The arm 71 is extended laterally from the cover body 16, and is providedso as to be slidable, at its other end portion, along the slide shaft757 via the bearing 713. At a peripheral face of the bearing 713, a gear7131 is formed. The arm 71 and the bearing 713 are placed on the raisingand lowering plate 758, and are slidable relative to the raising andlowering plate 758.

The rotation means 92 has: a motor 921 fixed on the raising and loweringplate 758; and a gear 922 rotationally driven by the motor 921. The gear922 is connected to the gear 7131 of the bearing 713.

An opening operation of this opening/closing means 7 will be carried outas follows. Specifically, upon operation of the cylinder drive means752, the raising and lowering plate 758 is raised by a predetermineddistance (e.g., the above-mentioned distance H) along the slide shaft757; as a result, the arm 71 placed onto the raising and lowering plate758 is raised by the above-mentioned predetermined distance, and thecover body 16 is raised by the above-mentioned predetermined distancewhile being kept in the horizontal state. Thereafter, the rotation means92 is operated to rotate the bearing 713, and to rotate the arm 71;thus, the cover body 16 moves laterally from above the treatment cell 11while forming an arc-shaped path. In other words, the cover body 16enters an open state. It should be noted that a closing operation iscarried out in a manner opposite to this opening operation.

Also in the opening/closing means 7 with the foregoing structure,operational effects similar to those of the opening/closing means 7shown in FIG. 15 can be achieved. In addition, since the cover body 16can be completely moved away from the treatment cell 11, the reliableopen state can be realized.

<Modified Structure of Drain Means 3>

(A) A first modified example will be described. As shown in FIG. 49, aflexible hose 37 is used instead of the discharge member including thereceiver 31 and the discharge pipe 32 shown in FIG. 20. Specifically, anupper end of the flexible hose 37 is connected to the discharge port 153of the receiving tank 15, and the connecting pipe 33 is connected to alower end of the flexible hose 37. The connecting pipe 33 is supportedby a center shaft 383 of a rotary table 382 via a fork 381, and isrotated similarly to the case shown in FIG. 20 along with the rotationof the rotary table 382. The rotary table 382 is supported by a rod 384,and is raised and lowered by a cylinder drive portion 385.

In this structure, the connecting pipe 33 is rotated so as to be locatedabove an inlet of an optional tank, and is lowered by the operation ofthe cylinder drive portion 385 so as to be connected to this inlet.

Also in this structure, operational effects similar to those of thedrain means 3 shown in FIG. 20 can be achieved. In addition, thestructure of the drain means 3 can be simplified, and furthermore, thepower required for rotation and/or raising and lowering can be reducedas compared with the case shown in FIG. 20.

(B) A second modified example will be described. As shown in FIG. 50,the connecting pipe 33 is not provided at the discharge pipe 32 but isprovided at the inlet of the tank. In FIG. 50, the connecting pipe 33 isprovided so as to be slidable up and down relative to the inlet 211 ofthe first tank 21, and is moved up and down relative to the inlet 211 bythe cylinder drive portion 34. Similarly, the connecting pipe 33 is alsoprovided at each of the inlet 241 of the second tank 24 and the inlet271 of the third tank 27.

In this structure, the receiver 31 is rotated; then, as shown in FIG.51, the vertical portion 322 of the discharge pipe 32 is located abovethe inlet 211 of the first tank 21, for example, the connecting pipe 33is raised by the cylinder drive portion 34, and the inlet 211 isconnected to the discharge pipe 32 via the connecting pipe 33.

Also in this structure, operational effects similar to those of thedrain means 3 shown in FIG. 20 can be achieved.

<Modified Structure of Anode Electrode Support Means>

(A) A first modified example will be described. FIG. 52 is a side viewshowing: the first anode electrode 41 and the support means 43 thereof;and the second anode electrode 46 and the support means 48 thereof. Thefirst support means 43 for the first anode electrode 41 has an arm 441extending laterally; a support body 442 extending up and down; and anabutment body 443.

The arm 441 supports, at its one end, the first anode electrode 41 andhas, at an upper part of its other end, a roller 444.

The support body 442 has: a cylinder drive means 445; a pole 446extending downward from the cylinder drive means 445; and a block 447fixed to a lower end portion of the pole 446. The arm 441 is supportedby a lower end of the block 447 at a position close to the roller 443 soas to be rotatable around a horizontal support shaft 448. It is to benoted that the rotation of the arm 441 is controlled such that the firstanode electrode 41 does not go down from the horizontal position of thearm 441.

The abutment body 443 is provided at a position at which the roller 444abuts against the abutment body from below when the arm 441 is raised bya predetermined distance H together with the first anode electrode 41while being kept in the horizontal state.

Moreover, the first support means 43 is provided with a nozzle 439 ofthe first surface treatment liquid supply means 22. The nozzle 439 issupported by the arm 441 in the vicinity of the first anode electrode41. The supply passage 440 leading to the nozzle 439 is fixed to theblock 447 and to the cylinder drive means 445. A portion 4401 of thesupply passage 440 between the block 447 and the cylinder drive means445 has a bellows structure, and is therefore extendable and shrinkable.

The second support means 48 of the second anode electrode 46 also has astructure similar to that of the first support means 43. That is, thesecond support means 48 has the second support means has an arm 481, asupport body 482, and an abutment body 483. The arm 481 has a roller484. The support body 482 has a cylinder drive means 485, a pole 486,and a block 487. The arm 481 is rotatable around a horizontal supportshaft 488. A nozzle 489 of the second surface treatment liquid supplymeans 24 is supported by the arm 481. A supply passage 460 leading tothe nozzle 489 has, at a portion 4601 located between the block 487 andthe cylinder drive means 485, a bellows structure, and is thereforeextendable and shrinkable.

The anode electrode support means with the foregoing structure allowsthe anode electrode to be detached/attached by only moving up/down thepole, thus making it possible to enhance the operating efficiency.

(B) A second modified example will be described. FIG. 53 is alongitudinal cross-sectional view of the support means in a case whereonly one anode electrode is used. In this example, the case where onlyone anode electrode is used refers to the case where only one type ofsurface treatment is carried out, or the case where an insoluble anodeis used.

In this support means, an anode electrode 93, including an anodeterminal 931 and an anode case 932, is provided in the center of thecover body 16. A lid portion 933 for covering the anode case 932 alsocovers the opening 161 of the cover body 16.

Further, the anode case 932 is provided at its inside with: a nozzle 94for supplying a surface treatment liquid; and a nozzle 95 for supplyingcleaning water. The inside of the anode case 932 is cleaned by thecleaning water supplied from the nozzle 95. The anode terminal 931 andthe nozzles 94 and 95 pass through the lid portion 933, and are fixed tothe lid portion 933.

Moreover, the water supply passage 53 of the first cleaning means 5 isprovided with a slit 59 that is opened radially inward.

In the foregoing structure, the opening/closing of the cover body 16 canbe performed in conjunction with the detachment/attachment of the anodeelectrode 93, thus making it possible to enhance the operatingefficiency. In addition, since the necessity for the support means forsupporting only the anode electrode can be eliminated, the structure ofthe apparatus can be simplified. Besides, since the opening 161 of thecover body 16 is covered by the lid portion 933, the surface treatmentliquid can be prevented from going through the opening 161 andscattering therefrom.

(C) A third modified example will be described. FIG. 54 is alongitudinal cross-sectional view of the support means in a case whereonly one anode electrode is used. In this example, the case where onlyone anode electrode is used refers to the case where an insoluble anodeis used. If an insoluble anode is used, there is no need to supply anymetal ion, and therefore, it is unnecessary to provide any anode casefor holding a metal serving as a metal ion supply source.

Hence, in this support means, the anode case and the nozzle 95 areeliminated as compared with the case shown in FIG. 53.

Also in the foregoing structure, effects similar to those of the caseshown in FIG. 53 can be achieved.

It should be noted that the surface treatment apparatus of the presentinvention can be used not only to carry out two types of electroplatingtreatments including the first electroplating treatment and secondelectroplating treatment as described above, but also to carry outsurface treatments described below.

In addition to an electroplating treatment, the surface treatmentsinclude a pre-treatment, a subsequent treatment, an electroless platingtreatment, an electrodeposition treatment, a composite platingtreatment, etc. Hereinafter, each of these treatments will be brieflydescribed.

<I> Pre-Treatment

Degreasing Process

A surface treatment liquid is an alkaline degreaser. No electric currenthas to be passed. This process cleans oil off a small object surface.

Electrolytic Degreasing Process

A surface treatment liquid is an alkaline solution. Electric current hasto be passed. In this process, a “cathode electrolysis method” uses eachsmall object as a cathode to clean off the soil of a small objectsurface by a hydrogen gas generated from the cathode, an “anodeelectrolysis method” uses each small object as an anode to clean off thesoil of the small object surface by an oxygen gas generated from theanode, and a “PR electrolysis method” periodically reverses thedirection of electric current, thereby cleaning off the soil of thesmall object surface by utilizing the advantages of the “cathodeelectrolysis method” and the “anode electrolysis method”.

Barrel Polishing Process

A surface treatment liquid is water, but does not have to be used. Noelectric current has to be passed. In this process, media for preventingflaws, a polishing agent and small objects are put into the treatmentcell and are mixed therein, thereby polishing a small object surface.When water is used, wet polishing is performed, and when no water isused, dry polishing is performed.

Alkaline Immersion Cleaning Process

A surface treatment liquid is an alkaline solution. No electric currenthas to be passed. This process cleans off the soil of a small objectsurface.

Pickling Process

A surface treatment liquid is an acid liquid. No electric current has tobe passed. This process removes rust, foreign matter and the like at asmall object surface, or corrodes the small object surface, therebyimproving the adherence between the small object surface and platingfilm.

Acid Electrolysis Process

A surface treatment liquid is an acid liquid. Electric current has to bepassed. This process removes severe rust at a small object surface. Thistreatment includes a method of using each small object as a cathode, anda method of using each small object as an anode.

Chemical Polishing Process

A surface treatment liquid is a chemical polishing liquid. No electriccurrent has to be passed. This process dissolves a convex region of asmall object surface in excess of a concave region thereof by an actionof the surface treatment liquid, thereby smoothing the small objectsurface.

Electropolishing Process

A surface treatment liquid is an electropolishing liquid. Electriccurrent has to be passed. In this process, each small object is used asan anode, and a convex region of a small object surface is dissolved inexcess, thereby smoothing the small object surface.

Neutralization Process

A surface treatment liquid is a neutralization liquid. No electriccurrent has to be passed. This process neutralizes a small objectsurface.

<II> Subsequent Treatment

Draining-Induced Tarnish Prevention Process

A surface treatment liquid is an aqueous solution containing a fewpercent of water-soluble silicon, surface-active agent or the like. Noelectric current has to be passed. In this process, the drying of smallobjects is promoted, thereby preventing occurrence of stain and tarnishat a small object surface.

Water-Soluble Resin Process

A surface treatment liquid is an aqueous solution in which water-solubleresin is dissolved. No electric current has to be passed. In thisprocess, small objects are immersed in the surface treatment liquid andare then dried, thereby forming an organic rust-inhibiting film at asmall object surface.

Chromating Process

A surface treatment liquid is a liquid containing chromic acid andmineral acid. No electric current has to be passed. In this process,small objects are immersed in the surface treatment liquid, therebyforming a chromating film at a small object surface. This process ismainly carried out after a galvanizing process has been performed, andthe chromating film is formed on the surface of a galvanized film,thereby improving the corrosion resistance of the galvanized film, andenhancing the appearance thereof.

<III> Electroless Plating Treatment

Immersion Plating Process

A surface treatment liquid is a solution containing ions of copper,nickel, tin, gold or the like. No electric current has to be passed. Inthis process, small objects made of base metal are immersed in thesolution containing noble metal ions; thus, electrons discharged due todissolution of a small object surface are transferred to the noble metalions, thereby forming a noble metal film at the small object surface.

Chemical Plating Process

A surface treatment liquid is a solution containing: ions of copper,nickel, tin, gold or the like; and a reducing agent or the like. Noelectric current has to be passed. In this process, electrons dischargeddue to oxidation of the reducing agent are transferred to the metalions, thereby forming a metal film at a small object surface.

<IV> Electrodeposition Treatment

Anion Electrodeposition Coating Process

A surface treatment liquid is an electrodeposition coating containingionic resin particles dispersed in water. Electric current has to bepassed. In this process, small objects are immersed in theelectrodeposition coating, voltage is applied to both of the smallobjects and the electrodeposition coating using each small object as ananode, and the resin particles are attracted to the small objects,thereby forming a resin film at a small object surface.

Cation Electrodeposition Coating Process

This process is similar to the anion electrodeposition coating processexcept that each small object is used as a cathode.

<V> Composite Plating Treatment

Composite Plating Process

A surface treatment liquid is a composite plating liquid containingmetal ions and non-metallic substance. Electric current has to bepassed. In this process, small objects are immersed in the surfacetreatment liquid and electric current is passed therethrough, therebyforming, at a small object surface, a film in which metal andnon-metallic substance are mixed with each other.

Chemical Composite Plating Process

This process is similar to the composite plating process except that noelectric current is passed.

Moreover, the rotary surface treatment apparatus of the presentinvention is normally operated to perform the foregoing steps when twotypes of surface treatments, requiring passage of electric current, arecarried out, but the steps <4>, <6>, <10> and <12> of the foregoingsteps are unnecessary when two types of surface treatments, requiring nopassage of electric current, are carried out. Further, when only onetype of surface treatment, requiring passage of electric current, iscarried out, the steps <9> to <14> of the foregoing steps areunnecessary. Furthermore, when only one type of surface treatment,requiring no passage of electric current, is carried out, the steps <9>to <14>, and <4> and <6> of the foregoing steps are unnecessary.

Second Embodiment

FIG. 55 is a perspective view of a surface treatment apparatus accordingto a second embodiment. The present embodiment relates to a so-called“single-liquid type” surface treatment apparatus for carrying out onetype of surface treatment in the single apparatus. The constituentelements, provided on a two-by-two basis in the surface treatmentapparatus of the first embodiment in order to use two types of surfacetreatment liquids, are provided on a one-by-one basis in the surfacetreatment apparatus of the present embodiment. The other structures ofthe present embodiment are similar to those of the first embodiment. InFIG. 55, the same reference characters as those in FIG. 1 to FIG. 54denote the same or equivalent constituent elements.

An opening/closing means 7 of this apparatus is the opening/closingmeans shown in FIG. 41, and a drain means 3 of this apparatus is thedrain means shown in FIG. 49.

A support means 97 for an anode electrode 96 of this apparatus has: anarm 971; a raising and lowering means 972; and a lateral movement means973. The anode electrode 96 is supported at one end of the arm 971. Theraising and lowering means 972 has: a pole (not shown); a cylinder drivemeans 974; and a slide shaft 975. The arm 971 is connected to an upperend of the pole, and is raised and lowered along the slide shaft 975 bythe cylinder drive portion 974. The lateral movement means 973 is formedso as to move the slide shaft 975 laterally along a guide shaft 976.

In this support means 97, the lateral movement means 973 is operated inthe state shown in FIG. 55, so that the slide shaft 975 moves laterallywhile holding the arm 971, and the anode electrode 96 is located above atreatment cell (not shown). Then, the raising and lowering means 972 isoperated, and the arm 971 is lowered. Thus, the anode electrode 96 isinserted into the treatment cell. On the other hand, the anode electrode96 is taken out from the treatment cell by performing these operationsreversely.

With the use of the constituent elements similar to those of the surfacetreatment apparatus of the first embodiment, the surface treatmentapparatus of the present embodiment is also operated similarly to thesurface treatment apparatus of the first embodiment. Accordingly, alsoin the surface treatment apparatus of the present embodiment,operational effects similar to those of the surface treatment apparatusof the first embodiment can be achieved.

INDUSTRIAL APPLICABILITY

The surface treatment apparatuses of the present invention are capableof preventing the inside and/or outside of the apparatuses from beingsoiled, and are thus industrially very valuable.

The invention claimed is:
 1. A surface treatment apparatus for carrying out a surface treatment on small objects while rotating a treatment cell containing the small objects, the surface treatment apparatus comprising: a treatment cell having a liquid flow-out portion that allows a liquid to flow out from inside to outside, and capable of containing the small objects; a receiving tank surrounding the treatment cell from below; a cover body provided so as to cover the receiving tank from above, the cover body having an opening at its center; a surface treatment liquid supply line that supplies a surface treatment liquid to the inside of the treatment cell; and a cleaning water supply line that supplies cleaning water to the inside of the treatment cell, wherein when the surface treatment liquid supply line is operated while the treatment cell is rotated, the surface treatment liquid is supplied to the inside of the treatment cell, and the surface treatment liquid is allowed to flow out from the treatment cell through the liquid flow-out portion, thereby carrying out a surface treatment on the small objects, wherein when the cleaning water supply line is operated while the treatment cell is rotated, the cleaning water is supplied to the inside of the treatment cell, and the cleaning water is allowed to flow out from the treatment cell through the liquid flow-out portion, thereby cleaning the small objects, wherein the apparatus further comprises a first cleaning device that ejects the cleaning water onto at least one of an inner face of the cover body and an outer face of the treatment cell, wherein when the first cleaning device is operated while the treatment cell is rotated, the at least one of the inner face of the cover body and the outer face of the treatment cell is cleaned, wherein the first cleaning device comprises at least one of a first ejection portion and a second ejection portion that ejects cleaning water, wherein the first ejection portion comprises an ejection port formed in a water supply passage provided along an edge of the opening of the cover body, and ejects the cleaning water onto the inner face of the cover body, wherein the second ejection portion comprises an ejection port formed in a water supply passage provided along the inner face of the cover body, and ejects the cleaning water onto the outer face of the treatment cell, and wherein an inner face of a lower end of a peripheral wall of the cover body is provided with a flange inclined inwardly downward, wherein the apparatus further comprises an opening/closing device that opens/closes the cover body relative to the receiving tank, wherein the opening/closing device raises/lowers the cover body to a predetermined height from a position at which the cover body covers the receiving tank, with the cover body kept in a horizontal state, and further moves the cover body from the predetermined height so that the cover body gets away from the receiving tank, wherein the opening/closing device comprises: an arm extending from the cover body; a rotary body provided at the other end side of the arm, and supported so as to be rotatable around a horizontal axis orthogonal to the arm; a horizontal support shaft that rotatably supports the arm; a support device that supports the arm so as to prevent a portion of the arm adjacent to the cover body from going down with the horizontal support shaft serving as a supporting point; a raising and lowering device that raises and lowers the horizontal support shaft together with the arm; and an abutment body against which the rotary body of the arm, raised to a predetermined height, abuts from below, and wherein upon raising of the horizontal support shaft, the cover body is raised while being kept in a horizontal state until the rotary body abuts against the abutment body, and after the rotary body has abutted against the abutment body, the cover body is raised while being inclined along with the rotation of the arm around the horizontal support shaft, and wherein the abutment body is provided above the rotary body at the other end side of the arm.
 2. A surface treatment apparatus for carrying out a surface treatment on small objects while rotating a treatment cell containing the small objects, the surface treatment apparatus comprising: a treatment cell having liquid flow-out portion that allows a liquid to flow out from inside to outside, and capable of containing the small objects; a receiving tank surrounding the treatment cell from below; a cover body provided so as to cover the receiving tank from above, the cover body having an opening at its center; a surface treatment liquid supply line that supplies a surface treatment liquid to the inside of the treatment cell; and a cleaning water supply line that supplies cleaning water to the inside of the treatment cell, wherein when the surface treatment liquid supply line is operated while the treatment cell is rotated, the surface treatment liquid is supplied to the inside of the treatment cell, and the surface treatment liquid is allowed to flow out from the treatment cell through the liquid flow-out portion, thereby carrying out a surface treatment on the small objects, wherein when the cleaning water supply line is operated while the treatment cell is rotated, the cleaning water is supplied to the inside of the treatment cell, and the cleaning water is allowed to flow out from the treatment cell through the liquid flow-out portion, thereby cleaning the small objects, wherein the apparatus further comprises an opening/closing device that opens/closes the cover body relative to the receiving tank, wherein the opening/closing device raises/lowers the cover body to a predetermined height from a position at which the cover body covers the receiving tank, with the cover body kept in a horizontal state, and further moves the cover body from the predetermined height so that the cover body gets away from the receiving tank, wherein the opening/closing device comprises: an arm extending from the cover body; a rotary body provided at the other end side of the arm, and supported so as to be rotatable around a horizontal axis orthogonal to the arm; a horizontal support shaft that rotatably supports the arm; a support device that supports the arm so as to prevent a portion of the arm adjacent to the cover body from going down with the horizontal support shaft serving as a supporting point; a raising and lowering device that raises and lowers the horizontal support shaft together with the arm; and an abutment body against which the rotary body of the arm, raised to a predetermined height, abuts from below, wherein upon raising of the horizontal support shaft, the cover body is raised while being kept in a horizontal state until the rotary body abuts against the abutment body, and after the rotary body has abutted against the abutment body, the cover body is raised while being inclined along with the rotation of the arm around the horizontal support shaft, and wherein the abutment body is provided above the rotary body at the other end side of the arm.
 3. A surface treatment apparatus for carrying out a surface treatment on small objects while rotating a treatment cell containing the small objects, the surface treatment apparatus comprising: a treatment cell having liquid flow-out portion that allows a liquid to flow out from inside to outside, and capable of containing the small objects; a receiving tank surrounding the treatment cell from below; a cover body provided so as to cover the receiving tank from above, the cover body having an opening at its center; a tank for containing a surface treatment liquid; a surface treatment liquid supply line that supplies the surface treatment liquid, contained in the tank, to the inside of the treatment cell; a cleaning water supply line that supplies cleaning water to the inside of the treatment cell; and a drain device that returns the surface treatment liquid, received by the receiving tank, to the tank containing the surface treatment liquid, and for flowing the cleaning water, received by the receiving tank, to a discharge portion, wherein when the surface treatment liquid supply line is operated while the treatment cell is rotated, the surface treatment liquid is supplied to the inside of the treatment cell, and the surface treatment liquid is allowed to flow out from the treatment cell through the liquid flow-out portion, thereby carrying out a surface treatment on the small objects, wherein when the cleaning water supply line is operated while the treatment cell is rotated, the cleaning water is supplied to the inside of the treatment cell, and the cleaning water is allowed to flow out from the treatment cell through the liquid flow-out portion, thereby cleaning the small objects, wherein the drain device comprises: a discharge member communicated with a discharge port of the receiving tank, the discharge member including a receiver and a discharge pipe; a connecting pipe provided so as to be connected to an end portion of the discharge member or to each of inlets of the tank and the discharge portion, in a manner movable up and down; a raising and lowering portion that moves the connecting pipe up and down; and a moving portion that moves the end portion of the discharge member, wherein the end portion of the discharge member is moved so as to be located above a selected one of the inlets of the tank and the discharge portion, and the connecting pipe is raised or lowered, thereby connecting the discharge member with the inlet via the connecting pipe, wherein the receiver includes a bottom face and a peripheral wall, the bottom face is inclined so as to be lowered toward a discharge port, and the discharge pipe is communicated with the discharge port and is fixed to the receiver, wherein the apparatus further comprises an opening/closing device that opens/closes the cover body relative to the receiving tank, wherein the opening/closing device raises/lowers the cover body to a predetermined height from a position at which the cover body covers the receiving tank, with the cover body kept in a horizontal state, and further moves the cover body from the predetermined height so that the cover body gets away from the receiving tank, wherein the opening/closing device comprises: an arm extending from the cover body; a rotary body provided at the other end side of the arm, and supported so as to be rotatable around a horizontal axis orthogonal to the arm; a horizontal support shaft that rotatably supports the arm; a support device that supports the arm so as to prevent a portion of the arm adjacent to the cover body from going down with the horizontal support shaft serving as a supporting point; a raising and lowering device that raises and lowers the horizontal support shaft together with the arm; and an abutment body against which the rotary body of the arm, raised to a predetermined height, abuts from below, and wherein upon raising of the horizontal support shaft, the cover body is raised while being kept in a horizontal state until the rotary body abuts against the abutment body, and after the rotary body has abutted against the abutment body, the cover body is raised while being inclined along with the rotation of the arm around the horizontal support shaft, and wherein the abutment body is provided above the rotary body at the other end side of the arm.
 4. A surface treatment apparatus for carrying out two types of surface treatments on small objects while rotating a treatment cell containing the small objects, the surface treatment apparatus comprising: a treatment cell having liquid flow-out portion that allows a liquid to flow out from inside to outside, and capable of containing the small objects; a receiving tank surrounding the treatment cell from below; a cover body provided so as to cover the receiving tank from above, the cover body having an opening at its center; two tanks for individually containing two types of surface treatment liquids; two surface treatment liquid supply lines that individually supply the surface treatment liquids, contained in the two tanks, to the inside of the treatment cell; a cleaning water supply line that supplies cleaning water to the inside of the treatment cell; and a drain device for returning the surface treatment liquid, received by the receiving tank, to the tank containing the surface treatment liquid, and for flowing the cleaning water, received by the receiving tank, to a discharge portion, wherein when the surface treatment liquid supply lines are operated while the treatment cell is rotated, the surface treatment liquid is supplied to the inside of the treatment cell, and the surface treatment liquid is allowed to flow out from the treatment cell through the liquid flow-out portion, thereby carrying out a surface treatment on the small objects, wherein when the cleaning water supply line is operated while the treatment cell is rotated, the cleaning water is supplied to the inside of the treatment cell, and the cleaning water is allowed to flow out from the treatment cell through the liquid flow-out portion, thereby cleaning the small objects, wherein the apparatus further comprises a first cleaning device that ejects the cleaning water onto at least one of an inner face of the cover body and an outer face of the treatment cell, wherein when the first cleaning device is operated while the treatment cell is rotated, the at least one of the inner face of the cover body and the outer face of the treatment cell is cleaned, wherein the apparatus further comprises an opening/closing device that opens/closes the cover body relative to the receiving tank, wherein the opening/closing device raises/lowers the cover body to a predetermined height from a position at which the cover body covers the receiving tank, with the cover body kept in a horizontal state, and further moves the cover body from the predetermined height so that the cover body gets away from the receiving tank, wherein the drain device comprises: a discharge member communicated with a discharge port of the receiving tank; a connecting pipe provided so as to be connected to an end portion of the discharge member or to each of inlets of the two tanks and the discharge portion, in a manner movable up and down; a raising and lowering portion that moves the connecting pipe up and down; and a moving portion that moves the end portion of the discharge member, wherein the end portion of the discharge member is moved so as to be located above a selected one of the inlets of the two tanks and the discharge portion, and the connecting pipe is raised or lowered, thereby connecting the discharge member with the inlet via the connecting pipe, wherein the opening/closing device comprises: an arm extending from the cover body; a rotary body provided at the other end side of the arm, and supported so as to be rotatable around a horizontal axis orthogonal to the arm; a horizontal support shaft that rotatably supports the arm; a support device that supports the arm so as to prevent a portion of the arm adjacent to the cover body from going down with the horizontal support shaft serving as a supporting point; a raising and lowering device that raises and lowers the horizontal support shaft together with the arm; and an abutment body against which the rotary body of the arm, raised to a predetermined height, abuts from below, and wherein upon raising of the horizontal support shaft, the cover body is raised while being kept in a horizontal state until the rotary body abuts against the abutment body, and after the rotary body has abutted against the abutment body, the cover body is raised while being inclined along with the rotation of the arm around the horizontal support shaft, and wherein the abutment body is provided above the rotary body at the other end side of the arm.
 5. The surface treatment apparatus according to claim 1, wherein the apparatus comprises a second cleaning device for ejecting cleaning water onto an inner face of the discharge member.
 6. The surface treatment apparatus according to claim 4, wherein the first cleaning device comprises at least one of a first ejection portion and a second ejection portion that ejects cleaning water, wherein the first ejection portion comprises an ejection port formed in a water supply passage provided along an edge of the opening of the cover body, and ejects the cleaning water onto the inner face of the cover body, and wherein the second ejection portion comprises an ejection port formed in a water supply passage provided along the inner face of the cover body, and ejects the cleaning water onto the outer face of the treatment cell.
 7. The surface treatment apparatus according to claim 4, wherein the apparatus comprises a second cleaning device that ejects cleaning water onto an inner face of the discharge member. 